A first series of nickel(II)complexes TrpyNi(II)X of the new tripyrrolic ligand 2,15-dimethyl-3,4,8,9,13,14-hexaethyltripyrrin with X = Cl, Br and I was prepared and characterized by spectroscopic and structural means. The coordination geometry found for the four-coordinate, paramagnetic bromo- and iodo-derivatives in the solid state can best be described as distorted trigonal-bipyramidal with one ligand missing in the trigonal plane. For the chloro derivative, this empty site is occupied in the crystal by a water ligand. As proton NMR studies on the paramagnetic TrpyNiCl reveal, an equilibrium exists between the four- and five-, but not a six-coordinate form, and for pyridine-N-oxide as the fifth ligand thermodynamic data of the ligand association could be obtained by a temperature dependent NMR titration study.
以2,15-二甲基-3,4,8,9,13,14-六乙基三吡啶为新三吡啶配体，制备了一系列以X = Cl、Br和I为配体的镍(II)配合物TrpyNi(II)X，并用光谱和结构手段对其进行了表征。四坐标、顺磁性的溴和碘固体衍生物的配位几何结构可以最好地描述为在三角平面上缺失一个配体的扭曲三角双锥体。对于氯衍生物，晶体中的这个空位被一个水配体占据。顺磁性TrpyNiCl的质子核磁共振研究表明，在4 -和5 -之间存在平衡，而不是6 -座标形式，对于吡啶- n -氧化物作为第五配体，可以通过温度相关的核磁共振滴定研究获得配体缔合的热力学数据。
{"title":"The first (tripyrrinato)nickel(ii) complexes, TrpyNiX with X = Cl, Br, I: synthesis, structures and solvent coordinationDedicated to Prof. Waldemar Adam on the occasion of his 65th birthday.","authors":"Martin Br ring, S. Prikhodovski, C. D. Brandt","doi":"10.1039/b209212n","DOIUrl":"https://doi.org/10.1039/b209212n","url":null,"abstract":"A first series of nickel(II)complexes TrpyNi(II)X of the new tripyrrolic ligand 2,15-dimethyl-3,4,8,9,13,14-hexaethyltripyrrin with X = Cl, Br and I was prepared and characterized by spectroscopic and structural means. The coordination geometry found for the four-coordinate, paramagnetic bromo- and iodo-derivatives in the solid state can best be described as distorted trigonal-bipyramidal with one ligand missing in the trigonal plane. For the chloro derivative, this empty site is occupied in the crystal by a water ligand. As proton NMR studies on the paramagnetic TrpyNiCl reveal, an equilibrium exists between the four- and five-, but not a six-coordinate form, and for pyridine-N-oxide as the fifth ligand thermodynamic data of the ligand association could be obtained by a temperature dependent NMR titration study.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81480165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iain D. Mackie, S. L. Hinchley, H. Robertson, D. Rankin, J. A. Pardoe, P. Timms
Gas-phase electron diffraction is a powerful technique for structural analysis of molecules in the gas phase, where they are free from packing forces that can occur in crystals. The compound B(BF2)3CO has been studied by gas-phase electron diffraction to compare its structure to that seen in the solid phase by low-temperature X-ray crystallography. Results show the gas-phase structure to be similar to that seen in the crystal. A model with C3 symmetry refined to give a C–O bond length of 115.8 pm and a C–B bond distance of 150.2 pm, which compare to values of 111.7 and 152.2 pm for the solid phase. The family of borane carbonyl compounds B(BX2)3CO (X = F, Cl, Br or I) have all been studied by ab initio calculations to show the effects of halogen substitution and to gauge the effects of electron correlation and basis set on each structure. Compounds X = F, Cl and Br give calculated structures with C3 symmetry in which the boron–halogen bonds lie coplanar with the C–O bond. In the case of X = I, the BI2 groups are twisted by approximately 35° from coplanar at the DFT level as a result of the large steric interactions between iodine atoms.
{"title":"The structures of borane carbonyl compounds B4X6CO (X = F, Cl, Br and I) by gas-phase electron diffraction and ab initio calculations","authors":"Iain D. Mackie, S. L. Hinchley, H. Robertson, D. Rankin, J. A. Pardoe, P. Timms","doi":"10.1039/B207192D","DOIUrl":"https://doi.org/10.1039/B207192D","url":null,"abstract":"Gas-phase electron diffraction is a powerful technique for structural analysis of molecules in the gas phase, where they are free from packing forces that can occur in crystals. The compound B(BF2)3CO has been studied by gas-phase electron diffraction to compare its structure to that seen in the solid phase by low-temperature X-ray crystallography. Results show the gas-phase structure to be similar to that seen in the crystal. A model with C3 symmetry refined to give a C–O bond length of 115.8 pm and a C–B bond distance of 150.2 pm, which compare to values of 111.7 and 152.2 pm for the solid phase. The family of borane carbonyl compounds B(BX2)3CO (X = F, Cl, Br or I) have all been studied by ab initio calculations to show the effects of halogen substitution and to gauge the effects of electron correlation and basis set on each structure. Compounds X = F, Cl and Br give calculated structures with C3 symmetry in which the boron–halogen bonds lie coplanar with the C–O bond. In the case of X = I, the BI2 groups are twisted by approximately 35° from coplanar at the DFT level as a result of the large steric interactions between iodine atoms.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86534628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Steyer, C. Jeunesse, D. Matt, R. Welter, M. Wesolek
The calixarene phosphites L1–L4 were obtained in high yield through reaction of PCl3/NEt3 with the monofunctionalised cone-calixarenes p-tert-butylcalix[4]arene(OH)3OR, in which the R substituents bear an oxygen donor ligand [R = CH2P(O)Ph2 (L1), CH2CO2Et (L2), CH2C(O)NEt2 (L3), CH2CH2OMe (L4)]. The calixarene core of the four ligands adopts a cone conformation and, hence, the phosphites become potential P,O-chelating systems. Phosphite L1 is remarkably stable towards aqueous NaOH, but the presence of slightly acidic water results in phosphonate formation. Slow oxidation of L1 in air afforded the corresponding mixed phosphine oxide–phosphate. In the complexes [RuCl2(p-cymene)L1], [cis-PtCl2(L1)2] (9), trans-[PdCl2(L1)2], [Pd(8-mq)Cl(Ln)] (8-mqH = 8-methylquinoline, n = 1–3), [Pd(dmba)Cl(L1)] (dmbaH = N,N-dimethylbenzylamine), [Pd(η3-C4H7)Cl(L2)], [Rh(acac)(CO)Ln] (n = 1–3) and [RhCl(CO)(L1)2], the phosphites behave as a monodentate phosphorus donor ligands. Owing to their steric crowding, the two cis-disposed ligands of complex 9 cannot freely rotate about their coordination axis. In the solid state, the calixarene backbones of complex 9 display a so-called ‘up-up-out-up’ conformation. Chelating phosphite behaviour was found in the cationic complexes [Pd(8-mq)Ln]BF4 (n = 1–3). In solution, the large, chelating P,O-loop of the latter complexes swings from one side of the metal plane to the other, the dynamics possibly being facilitated by the flexibility of the calixarene backbone. The four oxo-functionalised phosphites were tested as catalysts for 1-octene hydroformylation. The observed reaction rates lie in the range reported for other medium-bulky phosphites. Furthermore, the hydroformylation rate decreases as the donor strength of the side group increases, suggesting binding of the O-donor during catalysis. The L/B ratios lie in the range 1.4–3.6, the highest linear aldehyde selectivity being observed with the phosphite ester L3.
{"title":"Heterofunctionalised phosphites built on a calix[4]arene scaffold and their use in 1-octene hydroformylation. Formation of 12-membered P,O-chelate rings","authors":"S. Steyer, C. Jeunesse, D. Matt, R. Welter, M. Wesolek","doi":"10.1039/B204604K","DOIUrl":"https://doi.org/10.1039/B204604K","url":null,"abstract":"The calixarene phosphites L1–L4 were obtained in high yield through reaction of PCl3/NEt3 with the monofunctionalised cone-calixarenes p-tert-butylcalix[4]arene(OH)3OR, in which the R substituents bear an oxygen donor ligand [R = CH2P(O)Ph2 (L1), CH2CO2Et (L2), CH2C(O)NEt2 (L3), CH2CH2OMe (L4)]. The calixarene core of the four ligands adopts a cone conformation and, hence, the phosphites become potential P,O-chelating systems. Phosphite L1 is remarkably stable towards aqueous NaOH, but the presence of slightly acidic water results in phosphonate formation. Slow oxidation of L1 in air afforded the corresponding mixed phosphine oxide–phosphate. In the complexes [RuCl2(p-cymene)L1], [cis-PtCl2(L1)2] \u0000(9), trans-[PdCl2(L1)2], [Pd(8-mq)Cl(Ln)] \u0000(8-mqH = 8-methylquinoline, n \u0000= 1–3), [Pd(dmba)Cl(L1)] \u0000(dmbaH = \u0000N,N-dimethylbenzylamine), [Pd(η3-C4H7)Cl(L2)], [Rh(acac)(CO)Ln] (n \u0000= 1–3) and [RhCl(CO)(L1)2], the phosphites behave as a monodentate phosphorus donor ligands. Owing to their steric crowding, the two cis-disposed ligands of complex 9 cannot freely rotate about their coordination axis. In the solid state, the calixarene backbones of complex 9 display a so-called ‘up-up-out-up’ conformation. Chelating phosphite behaviour was found in the cationic complexes [Pd(8-mq)Ln]BF4 (n \u0000= 1–3). In solution, the large, chelating P,O-loop of the latter complexes swings from one side of the metal plane to the other, the dynamics possibly being facilitated by the flexibility of the calixarene backbone. The four oxo-functionalised phosphites were tested as catalysts for 1-octene hydroformylation. The observed reaction rates lie in the range reported for other medium-bulky phosphites. Furthermore, the hydroformylation rate decreases as the donor strength of the side group increases, suggesting binding of the O-donor during catalysis. The L/B ratios lie in the range 1.4–3.6, the highest linear aldehyde selectivity being observed with the phosphite ester L3.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87178716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two new open-framework solids, a zinc arsenate–oxalate, [NH3(CH2)3NH2(CH2)3NH3][Zn3(AsO4)(HAsO4)2(C2O4)], I, and a zinc arsenate, [{NH3(CH2)3NH2(CH2)3NH3}2][Zn6(AsO4)4(HAsO4)3]·H2O, II, have been synthesized in the presence of dipropylenetriamine (DPTA) under mild hydrothermal reaction conditions. Both I and II possess a three-dimensional architecture with channels. The structure of the zinc arsenate–oxalate, I, consists of anionic zinc arsenate–oxalate layers cross-linked by arsenate units giving rise to 10-membered channels. The zinc arsenate structure, II, on the other hand, is made from the linkages involving zinc arsenate layers and arsenate pillars. The structures of both I and II possess large number of hydrogen bond interactions involving the framework oxygen atoms and the hydrogen atoms of the amine molecule. The synthesis conditions employed and the close structural similarity between the two structures indicates that I could be the precursor for II.
{"title":"Hydrothermal synthesis and structure of a zinc arsenate–oxalate, [NH3(CH2)3NH2(CH2)3NH3][Zn3(AsO4)(HAsO4)2(C2O4)], and a zinc arsenate, [{NH3(CH3)2NH2(CH3)3NH3}2][Zn6(AsO4)4(HAsO4)3]·H2O, with three-dimensional structures","authors":"Sandip Chakrabarti, S. Natarajan","doi":"10.1039/B205874J","DOIUrl":"https://doi.org/10.1039/B205874J","url":null,"abstract":"Two new open-framework solids, a zinc arsenate–oxalate, [NH3(CH2)3NH2(CH2)3NH3][Zn3(AsO4)(HAsO4)2(C2O4)], I, and a zinc arsenate, [{NH3(CH2)3NH2(CH2)3NH3}2][Zn6(AsO4)4(HAsO4)3]·H2O, II, have been synthesized in the presence of dipropylenetriamine (DPTA) under mild hydrothermal reaction conditions. Both I and II possess a three-dimensional architecture with channels. The structure of the zinc arsenate–oxalate, I, consists of anionic zinc arsenate–oxalate layers cross-linked by arsenate units giving rise to 10-membered channels. The zinc arsenate structure, II, on the other hand, is made from the linkages involving zinc arsenate layers and arsenate pillars. The structures of both I and II possess large number of hydrogen bond interactions involving the framework oxygen atoms and the hydrogen atoms of the amine molecule. The synthesis conditions employed and the close structural similarity between the two structures indicates that I could be the precursor for II.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73221283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Baumeister, R. Alberto, K. Ortner, B. Spingler, P. Schubiger, T. Kaden
A series of NS3-open chain and cage ligands were synthesised and their complexation behaviour towards Ag(I) and Cu(I) studied. Crystal structures show that all open chain ligands form complexes in which the four donor atoms of the ligands coordinate the metal ions in a trigonal pyramidal geometry. For the NS3-cages, however, the ions are not in the centre of the cage, but show peripheral coordination resulting in polymeric crystal structures. The new NS3-aromatic cage ligand 18 binds Ag(I) peripherally giving a polymeric structure in the solid state and fluxional behaviour in solution. NMR evidence for equally populated central and peripheral coordination sites is coherent with results from DFT calculations.
{"title":"Central vs. peripheral Ag(i) coordination in NS3-open chain and cage ligands","authors":"J. Baumeister, R. Alberto, K. Ortner, B. Spingler, P. Schubiger, T. Kaden","doi":"10.1039/B205287C","DOIUrl":"https://doi.org/10.1039/B205287C","url":null,"abstract":"A series of NS3-open chain and cage ligands were synthesised and their complexation behaviour towards Ag(I) and Cu(I) studied. Crystal structures show that all open chain ligands form complexes in which the four donor atoms of the ligands coordinate the metal ions in a trigonal pyramidal geometry. For the NS3-cages, however, the ions are not in the centre of the cage, but show peripheral coordination resulting in polymeric crystal structures. The new NS3-aromatic cage ligand 18 binds Ag(I) peripherally giving a polymeric structure in the solid state and fluxional behaviour in solution. NMR evidence for equally populated central and peripheral coordination sites is coherent with results from DFT calculations.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73686019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Adams, I. Bartlett, N. Connelly, D. Harding, Owen D. Hayward, Antonio Martín, A. Orpen, M. J. Quayle, P. Rieger
X-Ray structural studies on the redox pair [Cr(CO)2(η-PhCCPh)(η-C6Me5H)]z (z = 0 and 1) show that one-electron oxidation of the neutral complex results in a shortening of the Cr–Calkyne bonds and a lengthening of the Cr–C(O) bonds, consistent with depopulation of a HOMO antibonding with respect to the metal–alkyne interaction. Oxidation leads to an increase in the substitutional lability of the Cr–CO bonds so that [Cr(CO)2(η-RCCR)(η-C6Me6)]+ (R = Ph or C6H4OMe-p) reacts with Lewis bases to give [Cr(CO)L(η-RCCR)(η-C6Me6)]+ {L = CNXyl, P(OMe)3 and P(OCH2)3CEt}, X-ray studies on which show a rotation of the alkyne to align with the remaining Cr–CO bond. ESR spectroscopic studies on [Cr(CO)L(η-RCCR)(η-C6Me6)]+ show delocalisation of the unpaired electron onto the alkyne ligand, consistent with its description as a three-electron donor. The cations [Cr(CO)L(η-RCCR)(η-C6Me6)]+ undergo both one-electron reduction and oxidation, and chemical oxidation of [Cr(CO){P(OCH2)3CEt}(η-p-MeOC6H4CCC6H4OMe-p)(η-C6Me6)]+ with AgPF6 gives the dication [Cr(CO){P(OCH2)3CEt}(η-p-MeOC6H4CCC6H4OMe-p)(η-C6Me6)]2+. Thus the two-electron alkyne of [Cr(CO)2(η-RCCR)(η-C6Me6)] is converted into the four-electron alkyne of [Cr(CO)L(η-RCCR)(η-C6Me6)]2+ by an ECE (E = electrochemical, C = chemical) process in which all of the intermediates have been fully characterised.
对氧化还原对[Cr(CO)2(η-PhCCPh)(η-C6Me5H)]z (z = 0和1)的x射线结构研究表明，中性络合物的单电子氧化导致Cr - calkyne键的缩短和Cr - c (O)键的延长，与金属-炔相互作用中HOMO反键的失序一致。氧化导致Cr - CO键的取代稳定性增加，使得[Cr(CO)2(η-RCCR)(η-C6Me6)]+ (R = Ph或C6H4OMe-p)与路易斯碱反应生成[Cr(CO)L(η-RCCR)(η-C6Me6)]+ {L = CNXyl, P(OMe)3和P(OCH2)3CEt}， x射线研究表明，炔的旋转与剩余的Cr - CO键排列一致。对[Cr(CO)L(η-RCCR)(η-C6Me6)]+的ESR光谱研究表明，未配对电子离域到炔配体上，符合其作为三电子供体的描述。阳离子[Cr(CO)L(η-RCCR)(η-C6Me6)]+经过单电子还原和氧化，[Cr(CO){P(OCH2) 3ceet}(η-p-MeOC6H4CCC6H4OMe-p)(η-C6Me6)]+与AgPF6化学氧化得到[Cr(CO){P(OCH2) 3ceet}(η-p-MeOC6H4CCC6H4OMe-p)(η-C6Me6)]2+。因此，[Cr(CO)2(η-RCCR)(η-C6Me6)]的双电子炔通过ECE (E =电化学，C =化学)过程转化为[Cr(CO)L(η-RCCR)(η-C6Me6)]2+的四电子炔，其中所有中间体都被充分表征。
{"title":"Redox routes to arenechromium complexes of two-, three- and four-electron alkynes; structure and bonding in paramagnetic [Cr(CO)L(η-RCCR)(η-arene)]+","authors":"C. Adams, I. Bartlett, N. Connelly, D. Harding, Owen D. Hayward, Antonio Martín, A. Orpen, M. J. Quayle, P. Rieger","doi":"10.1039/B206177P","DOIUrl":"https://doi.org/10.1039/B206177P","url":null,"abstract":"X-Ray structural studies on the redox pair [Cr(CO)2(η-PhCCPh)(η-C6Me5H)]z \u0000(z \u0000= 0 and 1) show that one-electron oxidation of the neutral complex results in a shortening of the Cr–Calkyne bonds and a lengthening of the Cr–C(O) bonds, consistent with depopulation of a HOMO antibonding with respect to the metal–alkyne interaction. Oxidation leads to an increase in the substitutional lability of the Cr–CO bonds so that [Cr(CO)2(η-RCCR)(η-C6Me6)]+ \u0000(R = Ph or C6H4OMe-p) reacts with Lewis bases to give [Cr(CO)L(η-RCCR)(η-C6Me6)]+ \u0000{L = CNXyl, P(OMe)3 and P(OCH2)3CEt}, X-ray studies on which show a rotation of the alkyne to align with the remaining Cr–CO bond. ESR spectroscopic studies on [Cr(CO)L(η-RCCR)(η-C6Me6)]+ show delocalisation of the unpaired electron onto the alkyne ligand, consistent with its description as a three-electron donor. The cations [Cr(CO)L(η-RCCR)(η-C6Me6)]+ undergo both one-electron reduction and oxidation, and chemical oxidation of [Cr(CO){P(OCH2)3CEt}(η-p-MeOC6H4CCC6H4OMe-p)(η-C6Me6)]+ with AgPF6 gives the dication [Cr(CO){P(OCH2)3CEt}(η-p-MeOC6H4CCC6H4OMe-p)(η-C6Me6)]2+. Thus the two-electron alkyne of [Cr(CO)2(η-RCCR)(η-C6Me6)] is converted into the four-electron alkyne of [Cr(CO)L(η-RCCR)(η-C6Me6)]2+ by an ECE (E = electrochemical, C = chemical) process in which all of the intermediates have been fully characterised.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81607653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K(VVO(H2O))(VIVO)O{O3P–(CH2)2–PO3} (labelled MIL-3K) is a vanado-ethylenediphosphonate whose previously reported hybrid framework reversibly dehydrates. Its anhydrous form (KVIV/V2O3{O3P–(CH2)2–PO3} or MIL-3Kan) has been determined from X-ray powder diffraction data in the centrosymmetric triclinic P (no. 2) space group with lattice parameters: a = 7.2375(1) , b = 8.1852(1), c = 9.8862(2) A, α = 83.2209(9), β = 65.223(1), γ = 76.492(1)°, V = 516.90(2), Z = 2. RF2 = 0.0920 and Rwp = 0.0157. The two structures of MIL-3K and MIL-3Kan are quite similar, just the square pyramidal coordination of one vanadium atom of the hydrate transforms into a VVO4 tetrahedron in the dehydrated form. This change induces the opening of eight-membered channels delimited by phosphonate tetrahedra and vanadium polyhedra in strict alternation.
{"title":"Structure determination of the anhydrous form of MIL-3K: a vanadodiphosphonate with a 3D hybrid framework","authors":"K. O. Kongshaug, D. Riou","doi":"10.1039/B205469H","DOIUrl":"https://doi.org/10.1039/B205469H","url":null,"abstract":"K(VVO(H2O))(VIVO)O{O3P–(CH2)2–PO3} \u0000(labelled MIL-3K) is a vanado-ethylenediphosphonate whose previously reported hybrid framework reversibly dehydrates. Its anhydrous form (KVIV/V2O3{O3P–(CH2)2–PO3} or MIL-3Kan) has been determined from X-ray powder diffraction data in the centrosymmetric triclinic P \u0000(no. 2) space group with lattice parameters: a \u0000= 7.2375(1) , b \u0000= 8.1852(1), c \u0000= 9.8862(2) \u0000A, α \u0000= 83.2209(9), β \u0000= 65.223(1), γ \u0000= 76.492(1)°, V \u0000= 516.90(2), Z \u0000= 2. RF2 \u0000= 0.0920 and Rwp \u0000= 0.0157. The two structures of MIL-3K and MIL-3Kan are quite similar, just the square pyramidal coordination of one vanadium atom of the hydrate transforms into a VVO4 tetrahedron in the dehydrated form. This change induces the opening of eight-membered channels delimited by phosphonate tetrahedra and vanadium polyhedra in strict alternation.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85075979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Baldamus, Christiane Berghof, M. L. Cole, David J Evans, E. Hey‐Hawkins, P. Junk
Treatment of N,N′-di(tolyl)formamidines ((Tol)NC(H)N(H)(Tol)) HFTolP (TolP = para-tolyl) and HFTolM (TolM = meta-tolyl) with potassium hydride affords the colourless crystalline formamidinate complexes [{K2(FTolP)2(THF)3}∞], 1, and [{(K2(FTolM)2(THF)3)·THF}∞], 2 when conducted in THF. An analogous HFTolP preparation in 1,2-dimethoxyethane yields the DME analogue of 1; [{K(FTolP)(DME)}∞], 3, whilst treatment of HFTolP with potassium hydride in toluene followed by stoichiometric addition of 18-crown-6 gives monomeric [K(FTolP)(18-crown-6)], 4. Compounds 1–4 have been characterised by spectroscopy (1H NMR, 13C NMR and FTIR) and single crystal XRD. In the solid-state 1–3 display one-dimensional polymeric structures that exhibit μ-η2:η2-coordinated formamidinates. These approach η3-diazaallyl contact by virtue of dinuclear bridging. Compound 4, the first example of a poly-ether crown adducted monomeric Group 1 amidinate, exhibits both inter- and intra-molecular C–H⋯O hydrogen bonding in the solid-state. Supramolecularly, this renders 4 a two-dimensional hydrogen-bonded polymer. Complexes 1–4 are discussed with respect to known potassium benzamidinate/guanidinate complexes and related amido-2-pyridyl ligand species.
{"title":"N,N′-Di(tolyl)formamidinate complexes of potassium: studies of ancillary donor imposed molecular and supramolecular structure","authors":"J. Baldamus, Christiane Berghof, M. L. Cole, David J Evans, E. Hey‐Hawkins, P. Junk","doi":"10.1039/B206165A","DOIUrl":"https://doi.org/10.1039/B206165A","url":null,"abstract":"Treatment of N,N′-di(tolyl)formamidines ((Tol)NC(H)N(H)(Tol)) HFTolP (TolP = para-tolyl) and HFTolM (TolM = meta-tolyl) with potassium hydride affords the colourless crystalline formamidinate complexes [{K2(FTolP)2(THF)3}∞], 1, and [{(K2(FTolM)2(THF)3)·THF}∞], 2 when conducted in THF. An analogous HFTolP preparation in 1,2-dimethoxyethane yields the DME analogue of 1; [{K(FTolP)(DME)}∞], 3, whilst treatment of HFTolP with potassium hydride in toluene followed by stoichiometric addition of 18-crown-6 gives monomeric [K(FTolP)(18-crown-6)], 4. Compounds 1–4 have been characterised by spectroscopy (1H NMR, 13C NMR and FTIR) and single crystal XRD. In the solid-state 1–3 display one-dimensional polymeric structures that exhibit μ-η2:η2-coordinated formamidinates. These approach η3-diazaallyl contact by virtue of dinuclear bridging. Compound 4, the first example of a poly-ether crown adducted monomeric Group 1 amidinate, exhibits both inter- and intra-molecular C–H⋯O hydrogen bonding in the solid-state. Supramolecularly, this renders 4 a two-dimensional hydrogen-bonded polymer. Complexes 1–4 are discussed with respect to known potassium benzamidinate/guanidinate complexes and related amido-2-pyridyl ligand species.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73603254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Ivanov, R. Nichiporuk, E. G. Mednikov, L. F. Dahl
Our exploratory research objective to obtain new high-nuclearity Au–Pd carbonyl phosphine clusters from reactions in DMF of preformed Pd10(CO)12(PEt3)6 with Au(PPh3)Cl in the presence of TlPF6 (a frequently utilized chloride-scavenger) has given rise unexpectedly in 40% yield to the first example of a heterometallic Tl–Pd carbonyl phosphine cluster, [Tl2Pd12(CO)9(PEt3)9]2+ (1-Et), as the [PF6]− salt. Its initial incorrect formulation as the unknown Au2Pd12 cluster, obtained from a well-refined low-temperature CCD X-ray diffraction analysis of its crystal structure, was primarily based upon its related molecular geometry to that of the previously reported [Au2Pd14(CO)9(PMe3)11]2+ (as the [PF6]− salt) prepared from an analogous reaction of Pd8(CO)8(PMe3)7 and Au(PCy3)Cl in the presence of TlPF6. (Because X-ray scattering occurs via the electrons of atoms, an assignment in the crystal-structure determination of 1-Et of the two independent “heavy” atoms as either Tl (at. no. 81) or Au (at. no. 79) would result in non-distinguishable refinements). 1-Et was originally characterized by IR and 31P{1H} NMR; attempted MALDI-ToF mass-spectrometric measurements were unsuccessful. The geometrically unprecedented pseudo-C3h core of 1-Et may now be described as edge-fusions of three trigonal bipyramidal Pd5 fragments to a central trigonal bipyramidal Tl2Pd3 kernel. Its formation was originally viewed as the condensation product of three partially ligated butterfly Pd4(CO)3(PEt3)3 fragments that are also linked to and stabilized by two capping naked Au+ cations. This proposed “structure-to-synthesis” approach led to the isolation of 1-Et in ca. 90% yield from the reaction in DMF of the butterfly Pd4(CO)5(PEt3)4 with the phosphine-scavenger Au(SMe2)Cl together with TlPF6. Our later realization and resulting conclusive evidence that its metal-core stoichiometry is Tl2Pd12 instead of Au2Pd12 was a consequence of: (1) our bothersome inability based upon a presumed Au2Pd12 core-geometry to interpret its complex 31P{1H} NMR spectrum despite 31P{1H} COSY experiments clearly showing couplings between the seven major resonances that are consistent with intramolecular processes involving only one species; (2) our subsequent direct preparation of the same Tl2Pd12 cluster (90% yield) from the reaction in THF of Pd4(CO)5(PEt3)4 with TlPF6 (mol. ratio, 3/2), and the ensuing low-temperature CCD X-ray determination revealing a virtually identical solid-state structure (as expected) but with 31P{1H} NMR measurements displaying an analogous complex spectrum that now can be interpreted; and (3) an elemental analysis (Tl, Au, Pd, P), which had been delayed because of the misleading confidence concerning our initially assigned stoichiometry, that ascertained its present formulation; noteworthy is that an elemental analysis of a sample of this compound would not disclose its true identity unless directly tested for Tl (and the absence of Au). Gradient-corrected DFT calculations p
{"title":"First high-nuclearity thallium–palladium carbonyl phosphine cluster, [Tl2Pd12(CO)9(PEt3)9]2+, and its initial mistaken identity as the unknown Au2Pd12 analogue: structure-to-synthesis approach concerning its formation","authors":"S. Ivanov, R. Nichiporuk, E. G. Mednikov, L. F. Dahl","doi":"10.1039/B204276M","DOIUrl":"https://doi.org/10.1039/B204276M","url":null,"abstract":"Our exploratory research objective to obtain new high-nuclearity Au–Pd carbonyl phosphine clusters from reactions in DMF of preformed Pd10(CO)12(PEt3)6 with Au(PPh3)Cl in the presence of TlPF6 \u0000(a frequently utilized chloride-scavenger) has given rise unexpectedly in 40% yield to the first example of a heterometallic Tl–Pd carbonyl phosphine cluster, [Tl2Pd12(CO)9(PEt3)9]2+ \u0000(1-Et), as the [PF6]− salt. Its initial incorrect formulation as the unknown Au2Pd12 cluster, obtained from a well-refined low-temperature CCD X-ray diffraction analysis of its crystal structure, was primarily based upon its related molecular geometry to that of the previously reported [Au2Pd14(CO)9(PMe3)11]2+ \u0000(as the [PF6]− salt) prepared from an analogous reaction of Pd8(CO)8(PMe3)7 and Au(PCy3)Cl in the presence of TlPF6. (Because X-ray scattering occurs via the electrons of atoms, an assignment in the crystal-structure determination of 1-Et of the two independent “heavy” atoms as either Tl (at. no. 81) or Au (at. no. 79) would result in non-distinguishable refinements). 1-Et was originally characterized by IR and 31P{1H} NMR; attempted MALDI-ToF mass-spectrometric measurements were unsuccessful. The geometrically unprecedented pseudo-C3h core of 1-Et may now be described as edge-fusions of three trigonal bipyramidal Pd5 fragments to a central trigonal bipyramidal Tl2Pd3 kernel. Its formation was originally viewed as the condensation product of three partially ligated butterfly Pd4(CO)3(PEt3)3 fragments that are also linked to and stabilized by two capping naked Au+ cations. This proposed “structure-to-synthesis” approach led to the isolation of 1-Et in ca. 90% yield from the reaction in DMF of the butterfly Pd4(CO)5(PEt3)4 with the phosphine-scavenger Au(SMe2)Cl together with TlPF6. Our later realization and resulting conclusive evidence that its metal-core stoichiometry is Tl2Pd12 instead of Au2Pd12 was a consequence of: (1) our bothersome inability based upon a presumed Au2Pd12 core-geometry to interpret its complex 31P{1H} NMR spectrum despite 31P{1H} COSY experiments clearly showing couplings between the seven major resonances that are consistent with intramolecular processes involving only one species; (2) our subsequent direct preparation of the same Tl2Pd12 cluster (90% yield) from the reaction in THF of Pd4(CO)5(PEt3)4 with TlPF6 \u0000(mol. ratio, 3/2), and the ensuing low-temperature CCD X-ray determination revealing a virtually identical solid-state structure (as expected) but with 31P{1H} NMR measurements displaying an analogous complex spectrum that now can be interpreted; and (3) an elemental analysis (Tl, Au, Pd, P), which had been delayed because of the misleading confidence concerning our initially assigned stoichiometry, that ascertained its present formulation; noteworthy is that an elemental analysis of a sample of this compound would not disclose its true identity unless directly tested for Tl (and the absence of Au). Gradient-corrected DFT calculations p","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78246380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thiourea dioxide was used as a precursor for sulfoxylate, SO22−, which is shown to reduce the methyl viologen dication to the fully reduced form, this is the first example of a direct study of the reduction with sulfoxylate; an important advantage of sulfoxylate and its parent compound thiourea dioxide, is their ability to reduce nitrite (the final product being nitrogen) and nitrous oxide in alkaline solutions in the absence of a catalyst.
{"title":"Reactions of methyl viologen and nitrite with thiourea dioxide. New opportunities for an old reductant","authors":"S. Makarov, E. V. Kudrik, R. Eldik, E. Naidenko","doi":"10.1039/B209195J","DOIUrl":"https://doi.org/10.1039/B209195J","url":null,"abstract":"Thiourea dioxide was used as a precursor for sulfoxylate, SO22−, which is shown to reduce the methyl viologen dication to the fully reduced form, this is the first example of a direct study of the reduction with sulfoxylate; an important advantage of sulfoxylate and its parent compound thiourea dioxide, is their ability to reduce nitrite (the final product being nitrogen) and nitrous oxide in alkaline solutions in the absence of a catalyst.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83278334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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