The first donor–acceptor complexes of Sb(III) and Bi(III) with telluroether ligands are reported, together with the crystal structure of [BiBr3(PhTeMe)].
{"title":"Synthesis and structural properties of the first bismuth(III) telluroether complex","authors":"W. Levason, N. Hill, G. Reid","doi":"10.1039/B209321A","DOIUrl":"https://doi.org/10.1039/B209321A","url":null,"abstract":"The first donor–acceptor complexes of Sb(III) and Bi(III) with telluroether ligands are reported, together with the crystal structure of [BiBr3(PhTeMe)].","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82760851","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}
The phosphine selenides, tris(dimethylamino)phosphine selenide, esters of selenophosphoric acid, and esters of selenophosphonic acid react with dihalogens and sulfuryl chloride to form halogenoselenophosphonium salts (P–SeX)+X−. The latter undergo deselenization via ligand exchange to form phosphonium salts (P–X)+X− and elemental selenium. The stability of these salts depends on the substituents at the phosphorus atom and the type of counter ion. It is likely that the phosphonium salts are in equilibrium with the corresponding phosphoranes, and this is demonstrated for esters containing an o-phenylene ligand. The structures of phosphonium salts, phosphoranes and other phosphorus compounds are supported by 31P NMR spectroscopy data and electrical conductivity. Additional evidence comes from addition reactions of halogenoselenophosphonium salts to cyclohexene.
{"title":"Studies on the interaction of phosphine selenides and their structural analogues wth dihalogens and sulfuryl chloride","authors":"E. Krawczyk, A. Skowrońska, J. Michalski","doi":"10.1039/B207019G","DOIUrl":"https://doi.org/10.1039/B207019G","url":null,"abstract":"The phosphine selenides, tris(dimethylamino)phosphine selenide, esters of selenophosphoric acid, and esters of selenophosphonic acid react with dihalogens and sulfuryl chloride to form halogenoselenophosphonium salts (P–SeX)+X−. The latter undergo deselenization via ligand exchange to form phosphonium salts (P–X)+X− and elemental selenium. The stability of these salts depends on the substituents at the phosphorus atom and the type of counter ion. It is likely that the phosphonium salts are in equilibrium with the corresponding phosphoranes, and this is demonstrated for esters containing an o-phenylene ligand. The structures of phosphonium salts, phosphoranes and other phosphorus compounds are supported by 31P NMR spectroscopy data and electrical conductivity. Additional evidence comes from addition reactions of halogenoselenophosphonium salts to cyclohexene.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90264025","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}
Claire P. Massen, Thomas V. Mortimer-Jones, R. Johnston
A detailed study is made of Pt, Pd and Pt–Pd bimetallic clusters, (PtPd)M, with up to 56 atoms, modelled by the many-body Gupta potential. A Genetic Algorithm is used to find the lowest energy structures for each nuclearity and composition. A variety of structure types (icosahedral, decahedral, fcc close-packed and disordered) are observed for Pt clusters. The Pd clusters have similar geometries to those of Pt, though more icosahedral clusters and fewer disordered structures are found than for Pt. Global minima are generally more difficult to find for the bimetallic Pt–Pd clusters, due to the presence of homotops (structures with identical geometries but with different arrangements of the Pt and Pd atoms) as well as geometrical isomers. The structures found for the bimetallic clusters are different to those of either of the pure element clusters, with more decahedral structures and fewer icosahedra. Segregation is observed in the Pt–Pd clusters, with most having Pt-rich cores and Pd-rich surfaces. This is explained in terms of the lower surface energy of Pd and the higher cohesive energy of Pt. Doping of Pt atoms into Pd clusters (and vice versa) is found to lead to significant changes in cluster geometry. The effect of varying the Pt–Pd parameters of the Gupta potential on the geometrical structures and atomic segregation in Pt–Pd clusters is investigated and the parameters obtained by averaging the Pt–Pt and Pd–Pd parameters are found to give best agreement with experiment. Our results are generally in good agreement with previous experimental and theoretical studies of Pt, Pd and Pt–Pd clusters and related alloy systems.
{"title":"Geometries and segregation properties of platinum–palladium nanoalloy clusters","authors":"Claire P. Massen, Thomas V. Mortimer-Jones, R. Johnston","doi":"10.1039/B207847C","DOIUrl":"https://doi.org/10.1039/B207847C","url":null,"abstract":"A detailed study is made of Pt, Pd and Pt–Pd bimetallic clusters, (PtPd)M, with up to 56 atoms, modelled by the many-body Gupta potential. A Genetic Algorithm is used to find the lowest energy structures for each nuclearity and composition. A variety of structure types (icosahedral, decahedral, fcc close-packed and disordered) are observed for Pt clusters. The Pd clusters have similar geometries to those of Pt, though more icosahedral clusters and fewer disordered structures are found than for Pt. Global minima are generally more difficult to find for the bimetallic Pt–Pd clusters, due to the presence of homotops (structures with identical geometries but with different arrangements of the Pt and Pd atoms) as well as geometrical isomers. The structures found for the bimetallic clusters are different to those of either of the pure element clusters, with more decahedral structures and fewer icosahedra. Segregation is observed in the Pt–Pd clusters, with most having Pt-rich cores and Pd-rich surfaces. This is explained in terms of the lower surface energy of Pd and the higher cohesive energy of Pt. Doping of Pt atoms into Pd clusters (and vice versa) is found to lead to significant changes in cluster geometry. The effect of varying the Pt–Pd parameters of the Gupta potential on the geometrical structures and atomic segregation in Pt–Pd clusters is investigated and the parameters obtained by averaging the Pt–Pt and Pd–Pd parameters are found to give best agreement with experiment. Our results are generally in good agreement with previous experimental and theoretical studies of Pt, Pd and Pt–Pd clusters and related alloy systems.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78235572","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}
Loïc Ropartz, K. Haxton, Douglas F. Foster, R. Morris, A. Slawin, D. Cole-Hamilton
Diphenylphosphine functionalised polyhedral oligomeric silsesquioxane (POSS) dendrimers are used as ligands for the rhodium catalysed hydroformylation of oct-1-ene showing unexpectedly high regioselectivity to the linear aldehyde nonan-1-al (l ∶ b = 14 ∶ 1). Comparative studies with the small molecule analogues, bis-diphenylphosphinopentane, Me2Si[CH2CH2PPh2]2 and Si[CH2CH2PPh2]4, clearly confirm the unusual selectivity of these bidentate dendritic ligands and show that a ‘positive dendritic effect’ occurs. This high selectivity is obtained with only one structure within the 1st and 2nd generation dendrimer (spacer of five atoms between the phosphorus atoms, and carbon–silicon linkage) whilst other frameworks (spacer of three and seven atoms between the P atoms, or carbon–oxygen–silicon linkage) lead to lower selectivity.
{"title":"Phosphine containing dendrimers for highly regioselective rhodium catalysed hydroformylation of alkenes: a positive ‘dendritic effect’","authors":"Loïc Ropartz, K. Haxton, Douglas F. Foster, R. Morris, A. Slawin, D. Cole-Hamilton","doi":"10.1039/B206597E","DOIUrl":"https://doi.org/10.1039/B206597E","url":null,"abstract":"Diphenylphosphine functionalised polyhedral oligomeric silsesquioxane (POSS) dendrimers are used as ligands for the rhodium catalysed hydroformylation of oct-1-ene showing unexpectedly high regioselectivity to the linear aldehyde nonan-1-al (l ∶ b = 14 ∶ 1). Comparative studies with the small molecule analogues, bis-diphenylphosphinopentane, Me2Si[CH2CH2PPh2]2 and Si[CH2CH2PPh2]4, clearly confirm the unusual selectivity of these bidentate dendritic ligands and show that a ‘positive dendritic effect’ occurs. This high selectivity is obtained with only one structure within the 1st and 2nd generation dendrimer (spacer of five atoms between the phosphorus atoms, and carbon–silicon linkage) whilst other frameworks (spacer of three and seven atoms between the P atoms, or carbon–oxygen–silicon linkage) lead to lower selectivity.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91214069","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. Costa Pessoa, M. J. Calhorda, I. Cavaco, I. Correia, M. Duarte, V. Félix, R. Henriques, M. Piedade, I. Tomaz
The dinuclear complex Na[V2O3(MeOsal-L-Ile)2]·H2O 1(MeOsal-L-Ile = 4-methoxysalicylidene-L-isoleucinate) has been prepared and characterised and its crystal structure determined. The molecule consists of two C-VO(MeOsal-L-Ile) units, the Schiff base ligand being approximately planar. Each unit exhibits a distorted square-pyramidal coordination geometry around the V atoms involving the O,N,O atoms of the Schiff base ligand and the bridging O(oxo) atom. The VIV–O–VV bridge is almost linear (angle: 170.9(3)°), indicating extensive electron delocalization, and the V–O(oxo) bond lengths are 1.811(5) and 1.836(5)A. Molecular mechanics (MM) and density functional theory (DFT) methods are used to calculate the structures and the main factors that determine the relative energies of the CL- and AL-[VIVO(sal-aa)(X)] diastereomeric complexes (aa = N-salicylidene-amino acidate, X = H2O or 2,2′-bipyridine). The results obtained indicate that for X = bpy the CL-diastereomers are more stable than the AL-diastereomers, and the energy differences increase with the degree of substitution on the β-carbon atom of the amino acid. For X = H2O the CL- and AL-diastereomers correspond to about the same energies. DFT methods are also used to calculate the IR spectrum of C-[VIVO(sal-L-Ala)(H2O)](sal-L-Ala = N-salicylidene-alaninate) which compares well with the experimental, and the gx, gy, gz, and Ax, Ay, Az parameters of the EPR spectra. The structure of [V2O3(HOsal-L-Gly)2]− was also calculated by DFT methods and compared with the X-ray structure of 1.
{"title":"Molecular modelling studies of N-salicylideneamino acidato complexes of oxovanadium(IV). Molecular and crystal structure of a new dinuclear LOVIV–O–VVOL mixed valence complex","authors":"J. Costa Pessoa, M. J. Calhorda, I. Cavaco, I. Correia, M. Duarte, V. Félix, R. Henriques, M. Piedade, I. Tomaz","doi":"10.1039/B205843J","DOIUrl":"https://doi.org/10.1039/B205843J","url":null,"abstract":"The dinuclear complex Na[V2O3(MeOsal-L-Ile)2]·H2O 1(MeOsal-L-Ile = 4-methoxysalicylidene-L-isoleucinate) has been prepared and characterised and its crystal structure determined. The molecule consists of two C-VO(MeOsal-L-Ile) units, the Schiff base ligand being approximately planar. Each unit exhibits a distorted square-pyramidal coordination geometry around the V atoms involving the O,N,O atoms of the Schiff base ligand and the bridging O(oxo) atom. The VIV–O–VV bridge is almost linear (angle: 170.9(3)°), indicating extensive electron delocalization, and the V–O(oxo) bond lengths are 1.811(5) and 1.836(5)A. Molecular mechanics (MM) and density functional theory (DFT) methods are used to calculate the structures and the main factors that determine the relative energies of the CL- and AL-[VIVO(sal-aa)(X)] diastereomeric complexes (aa = N-salicylidene-amino acidate, X = H2O or 2,2′-bipyridine). The results obtained indicate that for X = bpy the CL-diastereomers are more stable than the AL-diastereomers, and the energy differences increase with the degree of substitution on the β-carbon atom of the amino acid. For X = H2O the CL- and AL-diastereomers correspond to about the same energies. DFT methods are also used to calculate the IR spectrum of C-[VIVO(sal-L-Ala)(H2O)](sal-L-Ala = N-salicylidene-alaninate) which compares well with the experimental, and the gx, gy, gz, and Ax, Ay, Az parameters of the EPR spectra. The structure of [V2O3(HOsal-L-Gly)2]− was also calculated by DFT methods and compared with the X-ray structure of 1.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85254672","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}
New Pd(II), Pt(II), Re(III), Mo (VI) and Mo(V) complexes with 2-mercaptonicotinic acid (HnicSH), [Pd(PPh3)(HnicS)2]·0.5CH3OH 1, [Pd(HnicS)2]·CH3OH 2, [Pt(PPh3)(HnicS)2]·NEt3·H2O 3, [Pt(HnicS)2] 4, [Pt(bipy)(HnicS)2]·CH3OH 5, [Re(PPh3)(OCH3)(HnicS)2] 6, [ReI2(PPh3)2(HnicS)] 7, [MoO2(CH3NicS)2] 8 and [Mo2O3(CH3nicS)4]·DMF 9 have been prepared. The crystal structures of compounds 1, 3, 8 and [ReI2(PPh3)2(HnicS)]·0.5H2O·DMF (7·0.5H2O·DMF) were determined by X-ray diffraction. Complexes 1 and 3 contain two HnicS− ligands bonded in two different coordination modes: monodentate (S) and chelating (N,S). Complexes 7 and 8 contain only one HnicS− ligand which is bidentate (N,S). Infrared, 1H and 13C-{1H} NMR spectroscopic data for the complexes are presented. The Mo(VI) complex 8 is active towards oxygen atom transfer reactions and can catalyse the oxidation of benzoin and PPh3 with dmso; the catalysis occurs via the Mo(V) complex 9 which has been isolated and characterized.
{"title":"Coordination modes of 2-mercaptonicotinic acid: synthesis and crystal structures of palladium(II), platinum(II), rhenium(III) and molybdenum(VI) complexes","authors":"S. Quintal, H. Nogueira, V. Félix, M. Drew","doi":"10.1039/B206101E","DOIUrl":"https://doi.org/10.1039/B206101E","url":null,"abstract":"New Pd(II), Pt(II), Re(III), Mo (VI) and Mo(V) complexes with 2-mercaptonicotinic acid (HnicSH), [Pd(PPh3)(HnicS)2]·0.5CH3OH 1, [Pd(HnicS)2]·CH3OH 2, [Pt(PPh3)(HnicS)2]·NEt3·H2O 3, [Pt(HnicS)2] \u00004, [Pt(bipy)(HnicS)2]·CH3OH 5, [Re(PPh3)(OCH3)(HnicS)2] \u00006, [ReI2(PPh3)2(HnicS)] \u00007, [MoO2(CH3NicS)2] \u00008 and [Mo2O3(CH3nicS)4]·DMF 9 have been prepared. The crystal structures of compounds 1, 3, 8 and [ReI2(PPh3)2(HnicS)]·0.5H2O·DMF (7·0.5H2O·DMF) were determined by X-ray diffraction. Complexes 1 and 3 contain two HnicS− ligands bonded in two different coordination modes: monodentate (S) and chelating (N,S). Complexes 7 and 8 contain only one HnicS− ligand which is bidentate (N,S). Infrared, 1H and 13C-{1H} NMR spectroscopic data for the complexes are presented. The Mo(VI) complex 8 is active towards oxygen atom transfer reactions and can catalyse the oxidation of benzoin and PPh3 with dmso; the catalysis occurs via the Mo(V) complex 9 which has been isolated and characterized.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82464548","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}
A series of meso-η1-platiniometalloporphyrins comprising DPP (= dianion of 5,15-diphenylporphyrin) and the first row transition metal ions Mn(III), Co(II), Ni(II) and Zn(II) has been prepared. The syntheses, spectroscopy and voltammetry as well as crystal structures of several of these derivatives are reported. The –PtBr(PPh3)2 moiety attached to the macrocycle at the meso position is a strong electron donor, as shown by its effects on spectra, oxidation potentials and reactivity. The crystal structures of trans-[PtBr(MDPP)(PPh3)2]·0.5CH2Cl2, where M = Co (16), Ni (14) and Zn (17), and trans-[PtBr(NiDPPBr)(PPh3)2] were determined. The structures exhibit non-planar distortions of the macrocycle which are best described as hybrids of typical ruffled and saddled conformations.
制备了一系列由DPP(5,15-二苯基卟啉离子)和第一排过渡金属离子Mn(III)、Co(II)、Ni(II)和Zn(II)组成的中η - 1-铂金属卟啉。报道了这些衍生物的合成、光谱学和伏安法以及晶体结构。中观位置附着在大环上的-PtBr (PPh3)2片段对光谱、氧化势和反应活性的影响表明，它是一个强电子给体。测定了M = Co (16)， Ni (14)， Zn(17)时trans-[PtBr(NiDPPBr)(PPh3)2]·0.5CH2Cl2和trans-[PtBr(NiDPPBr)(PPh3)2]的晶体结构。该结构表现出大旋回的非平面畸变，最好描述为典型的褶皱和鞍状构象的杂化。
{"title":"Peripherally-metallated porphyrins: preparation, spectroscopic properties and structural studies of trans-[PtBr(MDPP)(PPh3)2] (DPP = dianion of 5,`15-diphenylporphyrin, M = MnCl, Co, Ni, Zn) and related meso-n1-organoplatinum porphyrins","authors":"M. J. Hodgson, P. Healy, M. Williams, D. Arnold","doi":"10.1039/B205295B","DOIUrl":"https://doi.org/10.1039/B205295B","url":null,"abstract":"A series of meso-η1-platiniometalloporphyrins comprising DPP (= dianion of 5,15-diphenylporphyrin) and the first row transition metal ions Mn(III), Co(II), Ni(II) and Zn(II) has been prepared. The syntheses, spectroscopy and voltammetry as well as crystal structures of several of these derivatives are reported. The –PtBr(PPh3)2 moiety attached to the macrocycle at the meso position is a strong electron donor, as shown by its effects on spectra, oxidation potentials and reactivity. The crystal structures of trans-[PtBr(MDPP)(PPh3)2]·0.5CH2Cl2, where M = Co (16), Ni (14) and Zn (17), and trans-[PtBr(NiDPPBr)(PPh3)2] were determined. The structures exhibit non-planar distortions of the macrocycle which are best described as hybrids of typical ruffled and saddled conformations.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73421268","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}
A. Molla-Abbassi, L. Eriksson, J. Mink, I. Persson, M. Sandström, M. Skripkin, Ann-Sofi Ullström, P. Lindqvist-Reis
The structure and bonding in bisaquamercury(II) trifluoromethanesulfonate, [Hg(OH2)2(CF3SO3)2]∞, and trisaquathallium(III) trifluoromethanesulfonate, [Tl(OH2)3(CF3SO3)3], have been studied by means of single-crystal X-ray diffraction, EXAFS and vibrational spectroscopy. The crystal structure of bisaquamercury(II) trifluoromethanesulfonate shows an unusual connectivity pattern. The mercury(II) ion strongly binds two water molecules axially with the Hg–O bond distance 2.11 A, and four oxygen atoms from four trifluoromethanesulfonate ions complete a tetragonally compressed octahedral coordination geometry, at the mean Hg–O distance 2.53 A. Two trifluoromethanesulfonate ions form double bridges between the bisaquamercury(II) entities giving rise to infinite >Hg(OH2)2 Hg(OH2)2< chains. The parallel chains are held together in layers by relatively strong hydrogen bonds with O(–H)⋯O distances in the range 2.688(9)–2.735(9) A. The O–D stretching vibrational frequencies of the hydrogen bonds in the partly deuterated compound occur in a broad band at about 2400 cm−1, bandwidth ca. 170 cm−1. The layers are connected only via van der Waals interactions between the protruding CF3 groups, consistent with the fragile sheet-like structure of the crystalline compound. Trisaquathallium(III) trifluoromethanesulfonate crystallises as molecular complexes where each thallium(III) ion binds three water molecules and three oxygen atoms from trifluoromethanesulfonate ions, with Tl–O bond distances in the range 2.18–2.24 A. A hydrogen bond network between the water molecules and trifluoromethanesulfonate ions with O(–H)⋯O distances in the range 2.65(1)–2.80(1) A holds the structure together. Raman and infrared spectra have been recorded and analysed. The changes in force constants and vibrational frequencies have been correlated with bond lengths for the S–O bond in the coordinated trifluoromethanesulfonate ion and for the Hg–O and Tl–O bonds, also including the hexaaquaions in the comparisons.
{"title":"Structure and bonding of bisaquamercury(II) and trisaquathallium(III) trifluoromethanesulfonate","authors":"A. Molla-Abbassi, L. Eriksson, J. Mink, I. Persson, M. Sandström, M. Skripkin, Ann-Sofi Ullström, P. Lindqvist-Reis","doi":"10.1039/B206021N","DOIUrl":"https://doi.org/10.1039/B206021N","url":null,"abstract":"The structure and bonding in bisaquamercury(II) trifluoromethanesulfonate, [Hg(OH2)2(CF3SO3)2]∞, and trisaquathallium(III) trifluoromethanesulfonate, [Tl(OH2)3(CF3SO3)3], have been studied by means of single-crystal X-ray diffraction, EXAFS and vibrational spectroscopy. The crystal structure of bisaquamercury(II) trifluoromethanesulfonate shows an unusual connectivity pattern. The mercury(II) ion strongly binds two water molecules axially with the Hg–O bond distance 2.11 A, and four oxygen atoms from four trifluoromethanesulfonate ions complete a tetragonally compressed octahedral coordination geometry, at the mean Hg–O distance 2.53 A. Two trifluoromethanesulfonate ions form double bridges between the bisaquamercury(II) entities giving rise to infinite >Hg(OH2)2 Hg(OH2)2< chains. The parallel chains are held together in layers by relatively strong hydrogen bonds with O(–H)⋯O distances in the range 2.688(9)–2.735(9) \u0000A. The O–D stretching vibrational frequencies of the hydrogen bonds in the partly deuterated compound occur in a broad band at about 2400 cm−1, bandwidth ca. 170 cm−1. The layers are connected only via van der Waals interactions between the protruding CF3 groups, consistent with the fragile sheet-like structure of the crystalline compound. Trisaquathallium(III) trifluoromethanesulfonate crystallises as molecular complexes where each thallium(III) ion binds three water molecules and three oxygen atoms from trifluoromethanesulfonate ions, with Tl–O bond distances in the range 2.18–2.24 A. A hydrogen bond network between the water molecules and trifluoromethanesulfonate ions with O(–H)⋯O distances in the range 2.65(1)–2.80(1) \u0000A holds the structure together. Raman and infrared spectra have been recorded and analysed. The changes in force constants and vibrational frequencies have been correlated with bond lengths for the S–O bond in the coordinated trifluoromethanesulfonate ion and for the Hg–O and Tl–O bonds, also including the hexaaquaions in the comparisons.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77893472","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}
V. C. Gibson, E. L. Marshall, D. Navarro-Llobet, Andrew J. P. White, D. Williams
The three-coordinate iron(II) complex, (But-BDI)FeOBut [But-BDI = HC(C(But)N-2,6-iPr2C6H3)2] is found to be a highly active initiator for the polymerisation of lactide and caprolactone at room temperature.
三配位铁(II)配合物(But- bdi)FeOBut [But- bdi = HC(C(But) n -2,6- ipr2c6h3)2]是室温下丙交酯和己内酯聚合的高活性引发剂。
{"title":"A well-defined iron(II) alkoxide initiator for the controlled polymerisation of lactide","authors":"V. C. Gibson, E. L. Marshall, D. Navarro-Llobet, Andrew J. P. White, D. Williams","doi":"10.1039/B209703F","DOIUrl":"https://doi.org/10.1039/B209703F","url":null,"abstract":"The three-coordinate iron(II) complex, (But-BDI)FeOBut \u0000[But-BDI = HC(C(But)N-2,6-iPr2C6H3)2] is found to be a highly active initiator for the polymerisation of lactide and caprolactone at room temperature.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78378807","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}
G. A. Horley, M. Mahon, M. Mazhar, K. Molloy, P. Haycock, C. P. Myers
Homoleptic antimony(III) β-diketonates Sb(thd)3 (Hthd = 2,2,6,6-tetramethyl-3,5-heptanedione) and Sb(fod)3 (Hfod = 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-heptanedione) have been synthesised from Sb(OEt)3 and three equivalents of the appropriate ligand. Both compounds have been characterised crystallographically and are monomeric with pseudo seven-coordination at antimony, where each ligand chelates the metal in an anisobidentate manner. Attempts to prepare Sb(hfac)3 (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) by the same route generated a compound of formula [(EtO)Sb(hfac)2]2 but in which the two β-diketonate ligands have combined to produce a functionalised 3,4-dihydro-2H-pyran ring; the dimer arises from a bridging ethoxy group. Heteroleptic (EtO)Sb(thd)2 has also been synthesised and crystallographically characterised as a monomeric structure in which the ethoxy group is terminal. In addition, Sb(OEt)2(fod) and Sb(OEt)4(thd) have been prepared for comparison.
{"title":"Antimony β-diketonates and alkoxide/β-diketonates: remarkable formation of a 3,4-dihydro-2H-pyran ring by coupling of 1,1,1,5,5,5-hexafluoro-2,4-pentanedione ligands","authors":"G. A. Horley, M. Mahon, M. Mazhar, K. Molloy, P. Haycock, C. P. Myers","doi":"10.1039/B208110E","DOIUrl":"https://doi.org/10.1039/B208110E","url":null,"abstract":"Homoleptic antimony(III) \u0000β-diketonates Sb(thd)3 \u0000(Hthd = 2,2,6,6-tetramethyl-3,5-heptanedione) and Sb(fod)3 \u0000(Hfod = 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-heptanedione) have been synthesised from Sb(OEt)3 and three equivalents of the appropriate ligand. Both compounds have been characterised crystallographically and are monomeric with pseudo seven-coordination at antimony, where each ligand chelates the metal in an anisobidentate manner. Attempts to prepare Sb(hfac)3 \u0000(Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) by the same route generated a compound of formula [(EtO)Sb(hfac)2]2 but in which the two β-diketonate ligands have combined to produce a functionalised 3,4-dihydro-2H-pyran ring; the dimer arises from a bridging ethoxy group. Heteroleptic (EtO)Sb(thd)2 has also been synthesised and crystallographically characterised as a monomeric structure in which the ethoxy group is terminal. In addition, Sb(OEt)2(fod) and Sb(OEt)4(thd) have been prepared for comparison.","PeriodicalId":17317,"journal":{"name":"Journal of The Chemical Society-dalton Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75492672","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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