F. D. Ramírez, S. Varbanov, C. Cécile, G. Muller, N. Fatin-Rouge, R. Scopelliti, J. Bünzli
The new lower rim functionalised macrocycle 5,11,17,23,29,35-hexa-tert-butyl-37,38,39,40,41,42-hexakis(dimethylphosphinoylmethoxy)calix[6]arene (B6bL6) has been synthesised. Temperature dependent 1H and 31P NMR studies indicate a mixture of conformers with a time-averaged C6v symmetry at 405 K in dmso-d6; ΔG≠ values for conformational interconversion processes are equal to 68(1) and 75(2) kJ mol−1 and reveal a semi-flexible macrocycle with alternate in-out cone conformation, a fact confirmed by molecular mechanics and dynamics calculations. B6bL6 crystallises as a dimer where the two calixarenes are linked through hydrogen bonding and surrounded by water and toluene molecules in the lattice. UV-Vis spectrophotometric titration of B6bL6 with La(III) in acetonitrile yields stability constants logβ1 = 9.8 and logβ2 = 19.6 for the 1 ∶ 1 and 1 ∶ 2 (Ln ∶ B6bL6) species, respectively. The corresponding complexes with La, Eu, Gd and Tb have been isolated and characterised. Lifetime determinations of the Eu(III) and Tb(III) complexes in acetonitrile solution are consistent with no or little interaction of water molecules in the inner co-ordination sphere. The new ligand sensitises reasonably well the luminescence of the Tb(III) (Qabs = 4.8% , τf = 2.1 ms, 1 ∶ 1 complex) and Eu(III) (Qabs = 2.5%, τ = 2.0 ms, 1 ∶ 2 complex) ions.
{"title":"A p-tert-butylcalix[6]arene bearing phosphinoyl pendant arms for the complexation and sensitisation of lanthanide ions","authors":"F. D. Ramírez, S. Varbanov, C. Cécile, G. Muller, N. Fatin-Rouge, R. Scopelliti, J. Bünzli","doi":"10.1039/B206238K","DOIUrl":"https://doi.org/10.1039/B206238K","url":null,"abstract":"The new lower rim functionalised macrocycle 5,11,17,23,29,35-hexa-tert-butyl-37,38,39,40,41,42-hexakis(dimethylphosphinoylmethoxy)calix[6]arene (B6bL6) has been synthesised. Temperature dependent 1H and 31P NMR studies indicate a mixture of conformers with a time-averaged C6v symmetry at 405 K in dmso-d6; ΔG≠ values for conformational interconversion processes are equal to 68(1) and 75(2) kJ mol−1 and reveal a semi-flexible macrocycle with alternate in-out cone conformation, a fact confirmed by molecular mechanics and dynamics calculations. B6bL6 crystallises as a dimer where the two calixarenes are linked through hydrogen bonding and surrounded by water and toluene molecules in the lattice. UV-Vis spectrophotometric titration of B6bL6 with La(III) in acetonitrile yields stability constants logβ1 = 9.8 and logβ2 = 19.6 for the 1 ∶ 1 and 1 ∶ 2 (Ln ∶ B6bL6) species, respectively. The corresponding complexes with La, Eu, Gd and Tb have been isolated and characterised. Lifetime determinations of the Eu(III) and Tb(III) complexes in acetonitrile solution are consistent with no or little interaction of water molecules in the inner co-ordination sphere. The new ligand sensitises reasonably well the luminescence of the Tb(III) (Qabs = 4.8% , τf = 2.1 ms, 1 ∶ 1 complex) and Eu(III) (Qabs = 2.5%, τ = 2.0 ms, 1 ∶ 2 complex) ions.","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":"76134486","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}
Paul Beagley, M. Blackie, K. Chibale, C. Clarkson, J. R. Moss, Peter J. Smith
The syntheses of the new compounds (7-chloroquinolin-4-yl)(2-dimethylaminomethylruthenocen-1-ylmethyl)amine 3 and N-(7-chloroquinolin-4-yl)-N′-(2-dimethylaminomethylruthenocen-1-ylmethyl)ethane-1,2-diamine 5 are reported. The reactions are compared to those previously reported for the preparation of the ferrocene analogues. The key step in the reaction is the regioselective synthesis of 2-dimethylaminomethylruthenocene carboxaldehyde 10 by deprotonation of dimethylaminomethylruthenocene with t-BuLi in diethyl ether, followed by the addition of DMF. In addition, 1′-dimethylaminomethylruthenocene carboxaldehyde 11 was also prepared leading to the unexpected synthesis of the 1,1′-isomers (7-chloroquinolin-4-yl)(1′-dimethylaminomethylruthenocen-1-ylmethyl)amine 17 and N-(7-chloroquinolin-4-yl)-N′-(1′-dimethylaminomethylruthenocen-1-ylmethyl)ethane-1,2-diamine 18. X-Ray crystal and molecular structures for compounds 3 and 17·H2O are reported. The 4-aminoquinoline complexes show high efficacy against the chloroquine sensitive and resistant strains of the Plasmodium falciparum parasite in vitro; these results are compared with those obtained for the analogous ferrocene compounds.
{"title":"Synthesis and antimalarial activity in vitro of new ruthenocene–chloroquine analogues","authors":"Paul Beagley, M. Blackie, K. Chibale, C. Clarkson, J. R. Moss, Peter J. Smith","doi":"10.1039/B205432A","DOIUrl":"https://doi.org/10.1039/B205432A","url":null,"abstract":"The syntheses of the new compounds (7-chloroquinolin-4-yl)(2-dimethylaminomethylruthenocen-1-ylmethyl)amine 3 and N-(7-chloroquinolin-4-yl)-N′-(2-dimethylaminomethylruthenocen-1-ylmethyl)ethane-1,2-diamine 5 are reported. The reactions are compared to those previously reported for the preparation of the ferrocene analogues. The key step in the reaction is the regioselective synthesis of 2-dimethylaminomethylruthenocene carboxaldehyde 10 by deprotonation of dimethylaminomethylruthenocene with t-BuLi in diethyl ether, followed by the addition of DMF. In addition, 1′-dimethylaminomethylruthenocene carboxaldehyde 11 was also prepared leading to the unexpected synthesis of the 1,1′-isomers (7-chloroquinolin-4-yl)(1′-dimethylaminomethylruthenocen-1-ylmethyl)amine 17 and N-(7-chloroquinolin-4-yl)-N′-(1′-dimethylaminomethylruthenocen-1-ylmethyl)ethane-1,2-diamine 18. X-Ray crystal and molecular structures for compounds 3 and 17·H2O are reported. The 4-aminoquinoline complexes show high efficacy against the chloroquine sensitive and resistant strains of the Plasmodium falciparum parasite in vitro; these results are compared with those obtained for the analogous ferrocene compounds.","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":"77706600","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}
U. Singh, S. Tyagi, C. L. Sharma, H. Görner, T. Weyhermüller
Reaction of GdCl3 and TbCl3 with one equivalent of the potassium salt of the tridentate ligand hydrotris(pyrazol-1-yl)borate [K(tp)] and two equivalents of sodium p-X-benzoate (X = H, Cl, Br and NO2) yielded the complexes 1–6 of composition [{(tp)Ln(μ-p-X-OBz)2}2] (Ln = Gd, Tb) whereas the reaction of TbCl3 with 2 equivalents of [K(tp)] and one equivalent of sodium azide, gave the tetranuclear complex [{(tp)2Tb(μ-N3)}4] (7). The crystal structures of the benzoate complexes (X = H) of Gd (1) and Tb (2) and their analogous p-Cl-benzoate derivatives with Gd (3) and Tb (4) have been determined. The compounds consist of a seven-coordinate tetrakis carboxylato bridged dimetal unit with two capping hydrotris(pyrazolyl)borate ligands. Unit cell determinations suggested that [{(tp)Tb(μ-p-Cl-OBz)2}2] (5), and [{(tp)Tb(μ-p-NO2-OBz)2}2] (6), are isostructural with (3) and (4). Single crystal X-Ray analysis of (7) revealed its tetranuclear structure comprising a cyclic 16-membered Tb4(μ-N3)4-unit with two hydrotris(pyrazol-1-yl)borate ligands bound to each of the terbium ions resulting in a tetragonal antiprismatic N8-coordination sphere. The luminescence properties of the unsubstituted and para-substituted Gd and Tb benzoate complexes have been studied in solution at room temperature.
{"title":"Synthesis, molecular structure and emission properties of benzoato-bridged lanthanide complexes with hydrotris(pyrazolyl)borate","authors":"U. Singh, S. Tyagi, C. L. Sharma, H. Görner, T. Weyhermüller","doi":"10.1039/B205053F","DOIUrl":"https://doi.org/10.1039/B205053F","url":null,"abstract":"Reaction of GdCl3 and TbCl3 with one equivalent of the potassium salt of the tridentate ligand hydrotris(pyrazol-1-yl)borate [K(tp)] and two equivalents of sodium p-X-benzoate (X = H, Cl, Br and NO2) yielded the complexes 1–6 of composition [{(tp)Ln(μ-p-X-OBz)2}2] \u0000(Ln = Gd, Tb) whereas the reaction of TbCl3 with 2 equivalents of [K(tp)] and one equivalent of sodium azide, gave the tetranuclear complex [{(tp)2Tb(μ-N3)}4] \u0000(7). The crystal structures of the benzoate complexes (X = H) of Gd (1) and Tb (2) and their analogous p-Cl-benzoate derivatives with Gd (3) and Tb (4) have been determined. The compounds consist of a seven-coordinate tetrakis carboxylato bridged dimetal unit with two capping hydrotris(pyrazolyl)borate ligands. Unit cell determinations suggested that [{(tp)Tb(μ-p-Cl-OBz)2}2] \u0000(5), and [{(tp)Tb(μ-p-NO2-OBz)2}2] \u0000(6), are isostructural with (3) and (4). Single crystal X-Ray analysis of (7) revealed its tetranuclear structure comprising a cyclic 16-membered Tb4(μ-N3)4-unit with two hydrotris(pyrazol-1-yl)borate ligands bound to each of the terbium ions resulting in a tetragonal antiprismatic N8-coordination sphere. The luminescence properties of the unsubstituted and para-substituted Gd and Tb benzoate complexes have been studied in solution 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":"82293175","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}
Christopher W. Baxter, Timothy C. Higgs, Anita C Jones, S. Parsons, P. Bailey, P. A. Tasker
Two novel high nuclearity copper(I) alkynyl complexes, [Cu16(hfac)8(CCBut)8] (1) and [Cu20(hfac)8(CCCH2Ph)12] (2), that consist of complicated alkynyl bridged Cu(I) cores ‘capped’ by peripheral hfac ligands have been synthesised and characterised by X-ray structure determination. The photoluminescent properties of 1 and 2 together with the clusters, [Cu18(hfac)10(CCBun)8] (4) and [Cu26(hfac)11(CCPrn)15] (5) and the monomeric species, [Cu(hfac)(HCCCH2OMe)] (3), [Cu(hfac)(Me3SiCCSiMe3)] (6) and [Cu(hfac)(COD)] (7) are reported. A comparison of the photoluminescent spectra of the high nuclearity species with the related monomeric complexes have shown that the cluster luminescence is derived from transitions within the delocalised Cu-hfac chelate ring.
{"title":"Luminescent high nuclearity Cu(I)-alkynyl clusters, [Cu16(hfac)8(3,3-dimethyl-1-butynyl)8] and [Cu20(hfac)8(3-phenyl-1-propynyl)12]","authors":"Christopher W. Baxter, Timothy C. Higgs, Anita C Jones, S. Parsons, P. Bailey, P. A. Tasker","doi":"10.1039/B207106C","DOIUrl":"https://doi.org/10.1039/B207106C","url":null,"abstract":"Two novel high nuclearity copper(I) alkynyl complexes, [Cu16(hfac)8(CCBut)8] \u0000(1) and [Cu20(hfac)8(CCCH2Ph)12] \u0000(2), that consist of complicated alkynyl bridged Cu(I) cores ‘capped’ by peripheral hfac ligands have been synthesised and characterised by X-ray structure determination. The photoluminescent properties of 1 and 2 together with the clusters, [Cu18(hfac)10(CCBun)8] \u0000(4) and [Cu26(hfac)11(CCPrn)15] \u0000(5) and the monomeric species, [Cu(hfac)(HCCCH2OMe)] \u0000(3), [Cu(hfac)(Me3SiCCSiMe3)] \u0000(6) and [Cu(hfac)(COD)] \u0000(7) are reported. A comparison of the photoluminescent spectra of the high nuclearity species with the related monomeric complexes have shown that the cluster luminescence is derived from transitions within the delocalised Cu-hfac chelate ring.","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":"87159465","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}
B. T. Patterson, J. Collins, Fiona M. Foley, F. Keene
The binding of the dinuclear ruthenium(II) complexes ΔΔ-[{Ru(Me2bpy)2}2(μ-bpm)]4+ and ΔΔ-[{Ru(bpy)2}(μ-bpm){Ru(Me2bpy)2}]4+ {bpy = 2,2′-bipyridine; Me2bpy = 4,4′-dimethyl-2,2′-bipyridine; bpm = 2,2′-bipyrimidine} to a tridecanucleotide containing a single adenine bulge has been studied by 1H NMR spectroscopy. The addition of either complex to d(CCGAGAATTCCGG)2 induced significant chemical shift changes for the base and sugar resonances of the residues at the bulge site (G3A4G5/C11C10). In NOESY spectra of the tridecanucleotide bound with either ruthenium species, NOEs were observed from the H1′ and H4′ protons of the nucleotide residues at the bulge site to the Me2bpy and bpm protons of the metal complex. These results indicate that the dinuclear ruthenium species selectively bind at the adenine bulge site in the minor groove. A simple model was constructed for the binding of the non-symmetrical ΔΔ-[{Ru(bpy)2}(μ-bpm){Ru(Me2bpy)2}]4+ complex, which shows that the minor groove has significantly widened to allow the relatively bulky complex to bind. As the metal complexes specifically bind at an adenine bulge site in a segment of DNA with an affinity considerably greater than that for standard duplex DNA, the results presented here suggest that non-intercalating dinuclear complexes may be excellent diagnostic agents for DNA bulged sequences.
{"title":"Dinuclear ruthenium(II) complexes as probes for DNA bulge sites","authors":"B. T. Patterson, J. Collins, Fiona M. Foley, F. Keene","doi":"10.1039/B208047H","DOIUrl":"https://doi.org/10.1039/B208047H","url":null,"abstract":"The binding of the dinuclear ruthenium(II) complexes ΔΔ-[{Ru(Me2bpy)2}2(μ-bpm)]4+ and ΔΔ-[{Ru(bpy)2}(μ-bpm){Ru(Me2bpy)2}]4+ \u0000{bpy = 2,2′-bipyridine; Me2bpy = 4,4′-dimethyl-2,2′-bipyridine; bpm = 2,2′-bipyrimidine} to a tridecanucleotide containing a single adenine bulge has been studied by 1H NMR spectroscopy. The addition of either complex to d(CCGAGAATTCCGG)2 induced significant chemical shift changes for the base and sugar resonances of the residues at the bulge site (G3A4G5/C11C10). In NOESY spectra of the tridecanucleotide bound with either ruthenium species, NOEs were observed from the H1′ and H4′ protons of the nucleotide residues at the bulge site to the Me2bpy and bpm protons of the metal complex. These results indicate that the dinuclear ruthenium species selectively bind at the adenine bulge site in the minor groove. A simple model was constructed for the binding of the non-symmetrical ΔΔ-[{Ru(bpy)2}(μ-bpm){Ru(Me2bpy)2}]4+ complex, which shows that the minor groove has significantly widened to allow the relatively bulky complex to bind. As the metal complexes specifically bind at an adenine bulge site in a segment of DNA with an affinity considerably greater than that for standard duplex DNA, the results presented here suggest that non-intercalating dinuclear complexes may be excellent diagnostic agents for DNA bulged sequences.","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":"91014382","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. Gallo, P. Mastrorilli, C. Nobile, G. Romanazzi, G. Suranna
The catalytic activity of several metal complexes in ionic liquids towards Michael addition of acetylacetone to methyl vinyl ketone is found to be strongly dependent on the presence of halogenide impurities of the solvent. The tested metal complexes are Ni(acac)2·2H2O, FeCl3·6H2O, Yb(TfO)3 (TfO = triflate) and Co(acac)2, and the ionic liquids used as solvents are [bmim]BF4 and [bmim]PF6 (bmim = 1-n-butyl-3-methylimidazolium). The rationalisation of the halogenide effect in terms of ligand exchange from the starting complex with the excess chloride of impure ionic liquids is demonstrated in the case of the cobalt based system where the formation of the poorly active CoCl42− species is detected by UV-Vis analysis.
{"title":"How does the presence of impurities change the performance of catalytic systems in ionic liquids? A case study: the Michael addition of acetylacetone to methyl vinyl ketone","authors":"V. Gallo, P. Mastrorilli, C. Nobile, G. Romanazzi, G. Suranna","doi":"10.1039/B207526A","DOIUrl":"https://doi.org/10.1039/B207526A","url":null,"abstract":"The catalytic activity of several metal complexes in ionic liquids towards Michael addition of acetylacetone to methyl vinyl ketone is found to be strongly dependent on the presence of halogenide impurities of the solvent. The tested metal complexes are Ni(acac)2·2H2O, FeCl3·6H2O, Yb(TfO)3 \u0000(TfO = triflate) and Co(acac)2, and the ionic liquids used as solvents are [bmim]BF4 and [bmim]PF6 \u0000(bmim = 1-n-butyl-3-methylimidazolium). The rationalisation of the halogenide effect in terms of ligand exchange from the starting complex with the excess chloride of impure ionic liquids is demonstrated in the case of the cobalt based system where the formation of the poorly active CoCl42− species is detected by UV-Vis analysis.","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":"82943742","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}
Divalent chlorochromium complexes bearing the TpiPr2 ligand [hydrotris(3,5-diisopropylpyrazolyl)borato], TpiPr2CrIICl(L) [L = 3,5-diisopropylpyrazole (1a), py (1b), bipy (2)] and TpiPr2CrII(μ-Cl)]2 (3), were prepared by treatment of CrCl2 with a TpiPr2 salt in the presence (1,2)/absence (3) of a donor (L). Reaction of 1 with benzyl chloride results in quantitative conversion to the corresponding trivalent dichlorochromium species, TpiPr2CrIIICl2(L) (6), while reaction with CH2Cl2 gives the methylene-inserted product, TpiPr2CrIIICl(CH2-L) 7, via a carbene intermediate, which is supported by cyclopropanation of styrene with CH2Cl2 in the presence of 3. The Cr(II) complex 1b induces reductive coupling of benzaldehyde to give a 3,4-diphenyl-2,5-dioxachromacyclopent-3-ene, TpiPr2Cr[κ2-O–C(Ph)C(Ph)–O] 8. Steric tuning effects of the TpiPr2 ligand leads to a variety of coordination geometries including five-coordinate square-pyramidal and trigonal-bipyramidal structures and a six-coordinate octahedral structure as revealed by crystallographic characterization.
{"title":"Di- and tri-valent chlorochromium complexes bearing hydrotris(3,5-diisopropylpyrazolyl)borato ligand (TpiPr2), TpiPr2CrCln(L) (n = 1, 2) and [TpiPr2Cr(μ-Cl)]2: flexible coordination behavior of the TpiPr2 ligand and reduction features of Cr(II) species","authors":"Ken-ichiro Sugawara, S. Hikichi, M. Akita","doi":"10.1039/B207326A","DOIUrl":"https://doi.org/10.1039/B207326A","url":null,"abstract":"Divalent chlorochromium complexes bearing the TpiPr2 ligand [hydrotris(3,5-diisopropylpyrazolyl)borato], TpiPr2CrIICl(L) \u0000[L = 3,5-diisopropylpyrazole (1a), py (1b), bipy (2)] and TpiPr2CrII(μ-Cl)]2 \u0000(3), were prepared by treatment of CrCl2 with a TpiPr2 salt in the presence (1,2)/absence (3) of a donor (L). Reaction of 1 with benzyl chloride results in quantitative conversion to the corresponding trivalent dichlorochromium species, TpiPr2CrIIICl2(L) \u0000(6), while reaction with CH2Cl2 gives the methylene-inserted product, TpiPr2CrIIICl(CH2-L) \u00007, via a carbene intermediate, which is supported by cyclopropanation of styrene with CH2Cl2 in the presence of 3. The Cr(II) complex 1b induces reductive coupling of benzaldehyde to give a 3,4-diphenyl-2,5-dioxachromacyclopent-3-ene, TpiPr2Cr[κ2-O–C(Ph)C(Ph)–O] \u00008. Steric tuning effects of the TpiPr2 ligand leads to a variety of coordination geometries including five-coordinate square-pyramidal and trigonal-bipyramidal structures and a six-coordinate octahedral structure as revealed by crystallographic characterization.","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":"90506243","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}
Richard K. Baldwin, M. Bennett, D. Hockless, P. Pertici, A. Verrazzani, G. U. Barretta, F. Marchetti, P. Salvadori
On reaction with the labile naphthalene complex [Ru(η6-C10H8)(η4-1,5-COD)], hex-3-yne undergoes stoichiometric cyclotrimerisation to form the hexaethylbenzene–ruthenium(0) complex [Ru(η6-C6Et6)(η4-1,5-COD)] 1. In the solid state and in solution the ethyl groups adopt a 1,4-proximal-2,3,5,6-distal arrangement, as shown by X-ray crystallography and NMR (1H, 13C-{1H}) spectroscopy. Treatment of 1 with HCl gives the binuclear ruthenium(II) complex [{RuCl(η6-C6Et6)}2(μ-Cl)2] 2, whose arene ligands adopt a transoid arrangement about the Ru2Cl2 moiety; in turn 2 reacts with methanolic NH4PF6 to give the salt [Ru2(μ-Cl)3(η6-C6Et6)2]PF6, [3]PF6. The ethyl group conformations in crystalline 2 and [3]PF6 are all-distal and 1,3,5-proximal-2,4,6-distal, respectively, whereas only the latter conformation is present in both compounds in dichloromethane or methanol solutions at low temperature according to 13C-{1H} NMR spectroscopy. The ν(Ru–Cl) band patterns in the IR spectra of 2 in the solid state and dichloromethane solution are almost identical, indicating that the neutral di-μ-chloro species predominates in solution at room temperature. However, the appearance at −50 °C of a resonance due to free chloride ion in the 35Cl NMR spectrum of complex 2 suggests that reversible formation of [3]Cl may be favoured at low temperature. Dilute (ca. 10−3 M) solutions of 2 in dichloromethane and methanol behave as 1 ∶ 1 electrolytes consistent with the presence of [3]Cl under these conditions. At room temperature the ethyl groups of η6-C6Et6 in 1, 2 and [3]PF6 are equivalent on the NMR time-scale as a consequence of rotation about the arene–methylene bond and, possibly, rotation of the arene about the arene–metal bond. In the crystalline adducts [RuCl2(η6-C6Et6)(L)] (L = PMe34, PPh35) the ethyl groups are all distal and remain equivalent on the NMR time-scale in solution from room temperature to −97 °C. The results confirm conclusions, based primarily on studies of Group 6 carbonyl complexes, that the different conformations of η6-C6Et6 have very similar energies.
{"title":"Synthesis, structures and dynamic NMR spectra of η6-hexaethylbenzene complexes of ruthenium(0) and ruthenium(II)","authors":"Richard K. Baldwin, M. Bennett, D. Hockless, P. Pertici, A. Verrazzani, G. U. Barretta, F. Marchetti, P. Salvadori","doi":"10.1039/B204875M","DOIUrl":"https://doi.org/10.1039/B204875M","url":null,"abstract":"On reaction with the labile naphthalene complex [Ru(η6-C10H8)(η4-1,5-COD)], hex-3-yne undergoes stoichiometric cyclotrimerisation to form the hexaethylbenzene–ruthenium(0) complex [Ru(η6-C6Et6)(η4-1,5-COD)] \u00001. In the solid state and in solution the ethyl groups adopt a 1,4-proximal-2,3,5,6-distal arrangement, as shown by X-ray crystallography and NMR (1H, 13C-{1H}) spectroscopy. Treatment of 1 with HCl gives the binuclear ruthenium(II) complex [{RuCl(η6-C6Et6)}2(μ-Cl)2] \u00002, whose arene ligands adopt a transoid arrangement about the Ru2Cl2 moiety; in turn 2 reacts with methanolic NH4PF6 to give the salt [Ru2(μ-Cl)3(η6-C6Et6)2]PF6, [3]PF6. The ethyl group conformations in crystalline 2 and [3]PF6 are all-distal and 1,3,5-proximal-2,4,6-distal, respectively, whereas only the latter conformation is present in both compounds in dichloromethane or methanol solutions at low temperature according to 13C-{1H} NMR spectroscopy. The ν(Ru–Cl) band patterns in the IR spectra of 2 in the solid state and dichloromethane solution are almost identical, indicating that the neutral di-μ-chloro species predominates in solution at room temperature. However, the appearance at −50 °C of a resonance due to free chloride ion in the 35Cl NMR spectrum of complex 2 suggests that reversible formation of [3]Cl may be favoured at low temperature. Dilute (ca. 10−3 M) solutions of 2 in dichloromethane and methanol behave as 1 ∶ 1 electrolytes consistent with the presence of [3]Cl under these conditions. At room temperature the ethyl groups of η6-C6Et6 in 1, 2 and [3]PF6 are equivalent on the NMR time-scale as a consequence of rotation about the arene–methylene bond and, possibly, rotation of the arene about the arene–metal bond. In the crystalline adducts [RuCl2(η6-C6Et6)(L)] \u0000(L = PMe34, PPh35) the ethyl groups are all distal and remain equivalent on the NMR time-scale in solution from room temperature to −97 °C. The results confirm conclusions, based primarily on studies of Group 6 carbonyl complexes, that the different conformations of η6-C6Et6 have very similar energies.","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":"86604852","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}
Phosphines are traditional Lewis bases or ligands in transition metal complexes. In spite of their electron-rich (lone pair bearing) nature, an extensive coordination chemistry is developing for Lewis acidic phosphines, which highlights a new synthetic methodology leading to new structure and bonding.
{"title":"New synthetic opportunities using Lewis acidic phosphines","authors":"N. Burford, P. Ragogna","doi":"10.1039/B208715D","DOIUrl":"https://doi.org/10.1039/B208715D","url":null,"abstract":"Phosphines are traditional Lewis bases or ligands in transition metal complexes. In spite of their electron-rich (lone pair bearing) nature, an extensive coordination chemistry is developing for Lewis acidic phosphines, which highlights a new synthetic methodology leading to new structure and bonding.","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":"84323917","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 2-dimensional lithiumfluoroberyllate compounds, that possess identical anionic sheet topologies, have been synthesised from aqueous solutions under hydrothermal and ambient pressure conditions. The structures of [Li2Be2F8][C2N2H10], 1, and [Li2Be2F8][CH3NH3]2·[H2O]2, 2, consist of inorganic layers, constructed from linked [MF4] (M = Li, Be) tetrahedra with organic templating cations incorporated between the sheets. For the ethylenediammonium cation, 1, the structure is a C-centred monoclinic cell, (space group C2/c), whereas the methylamine hydrate, 2, crystallises in P21/c, The interlayer regions possess corrugated topologies within which the organic moieties lie with the amine groups directed into the larger pockets. Hydrogen bonding exists between ions situated on the protonated amine groups on the templating species and electronegative fluoride ions.
{"title":"2-Dimensional sheet structures from linked metal fluoride tetrahedra","authors":"L. A. Gerrard, M. Weller","doi":"10.1039/B206469C","DOIUrl":"https://doi.org/10.1039/B206469C","url":null,"abstract":"Two 2-dimensional lithiumfluoroberyllate compounds, that possess identical anionic sheet topologies, have been synthesised from aqueous solutions under hydrothermal and ambient pressure conditions. The structures of [Li2Be2F8][C2N2H10], 1, and [Li2Be2F8][CH3NH3]2·[H2O]2, 2, consist of inorganic layers, constructed from linked [MF4] \u0000(M = Li, Be) tetrahedra with organic templating cations incorporated between the sheets. For the ethylenediammonium cation, 1, the structure is a C-centred monoclinic cell, (space group C2/c), whereas the methylamine hydrate, 2, crystallises in P21/c, The interlayer regions possess corrugated topologies within which the organic moieties lie with the amine groups directed into the larger pockets. Hydrogen bonding exists between ions situated on the protonated amine groups on the templating species and electronegative fluoride ions.","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":"80836357","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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