Biomedical subjects
Publications and source records attributed to Herbert W. Roesky.
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Organometallic fluorides of main group and transition elements are described starting with monocyclopentadienyl derivatives of the group 4 metals and their adducts with AlMe(3). Host-guest type compounds such as [(eta(5)-C(5)Me(4)Et)TiF(3)](4)CaF(2) and supramolecular assemblies such as Ag(S(4)(CN)(2))(2)AsF(6) are also observed. Finally some aluminum-fluorine compounds including derivatives of aluminum(I) are described.
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The reactions between t-BuP(O)(OH)(2) and equimolar quantities of MGaMe(4) (M = Na, K) yield ionic and alkali metal containing molecular gallophosphonates [Na(4)(&mgr;(2)-OH(2))(2)(THF)(2)][(Me(2)GaO(3)PBu-t)(2)](2).2THF (2) and [K(THF)(6)][K(5)(THF)(2){(Me(2)GaO(3)PBu-t)(2)}(3)] (3), respectively. Compounds 2 and 3are soluble in common organic solvents and have been characterized by means of analytical and spectroscopic techniques, as well as by single-crystal X-ray diffraction studies. These compounds represent the rare examples of molecular ionic phosphonate cages which contain coordinated Na(+) or K(+) ions. Compound 2 is constructed from two eight-membered Ga(2)O(4)P(2) gallium phosphonate rings which sandwich a central Na(4)(H(2)O)(2) unit. In the case of 3, three eight-membered Ga(2)O(4)P(2) gallium phosphonate units envelope an aggregated K(5) core which exists in the form of a trigonal-bipyramidal polyhedron. The Na(+) and K(+) ions in 2 and 3 are also coordinated by the endocyclic oxygen atoms of the eight-membered gallophosphonate crowns, apart from the regular exocyclic P-O coordination. Unlike the lithium gallophosphonate [Li(4)(THF)(4)][{(MeGaO(3)PBu-t)(3)(&mgr;(3)-O(2))}(2)] (1), compounds 2 and 3 do not undergo any clean cage conversion reaction in the presence of 15-crown-5 and 18-crown-6, respectively.
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A facile, high-yield synthesis of Cl(3)VNSiMe(3) (1) is reported. 1 and the metal nitride halides Cl(3)MoN and Cl(3)WN react with [{(Me(2)N)(2)PNH(2)}(2)N](+)Cl(-) to form the six-membered metallacyclophosphazenes [(Me(2)N)(2)PN](2)VCl(2) (2), [(Me(2)N)(2)PN](2)MoCl(3).MeCN (3), and [(Me(2)N)(2)PN](2)WCl(3).MeCN (4), respectively. The X-ray structure determinations of 2 and 3 show the compounds to have planar six-membered rings of distorted geometry.
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The reaction of Ti(NMe(2))(4) with 2 equiv of Me(3)SiN(3) in toluene solution affords a dark red polymeric material of composition [Ti(NMe(2))(2)(N(3))(2)](n) (1). If the reaction is carried out in pyridine (py) solution, dark red, crystalline [Ti(NMe(2))(2)(N(3))(2)(py)(2)] (2) is formed. Analogous reactions of Ti(NMe(2))(4) with 2 or 1 equiv of Me(3)SiN(3) in the presence of 1 equiv of bipyridyl (bipy) in toluene solution afford brown crystals of [Ti(NMe(2))(2)(N(3))(2)(bipy)] (3) and dark red crystals of [Ti(NMe(2))(3)(N(3))(bipy)] (4), respectively. Crystallographic data for 2: orthorhombic, C222(1), a = 7.120(1) Å, b = 15.899(3) Å, c = 16.946(4) Å, V = 1918.3(6) Å(3), rho = 1.310 g/cm(3), Z = 4. Crystallographic data for 3: monoclinic, I2/a, a = 7.358(2) Å, b = 16.808(4) Å, c = 14.837(6) Å, beta = 95.40(2) degrees, V = 1826.8(1) Å(3), rho = 1.368 g/cm(3), Z = 4. Crystallographic data for 4: monoclinic, P2(1)/c, a = 15.682(2) Å, b = 8.814(1) Å, c = 15.128(1) Å, beta = 108.39(1) degrees, V = 1984.2(4) Å(3), rho = 1.267 g/cm(3), Z = 4. Compounds 1 and 2 deposit thin films of titanium nitride (TiN) on silica and/or nickel substrates in the temperature range 300-400 degrees C. The TiN films deposited from precursor 2 are superior to those deposited from 1.
Reactions of LnCl(3) (Ln = Nd, Gd, Yb) and [{Me(2)SiN(R)Li}(2)] (R = t-Bu, Ph) give the chloride-bridged dimers [{{(t-Bu)NSiMe(2)SiMe(2)N(t-Bu)}Ln(&mgr;-Cl)(THF)}(2)] (1, Ln = Nd; 2, Ln = Gd; 3, Ln = Yb) and [{{(Ph)NSiMe(2)SiMe(2)N(Ph)}Ln(&mgr;-Cl)(THF)(2)}(2)] (4, Ln = Nd; 5, Ln = Gd; 6, Ln = Yb) in good yields. Compounds 2 and 5 were structurally characterized by X-ray crystallography: 2, triclinic, P&onemacr;, a = 10.321(2) Å, b = 11.116(2) Å, c = 13.434(3) Å, alpha = 107.57(3) degrees, beta = 111.31(3) degrees, gamma = 90.67(3) degrees, V = 1356.1(5) Å(3), Z = 1, R = 0.0233; 5, monoclinic, P2(1)/n, a = 13.913(13) Å, b = 12.914(9) Å, c = 16.434(14) Å, beta = 105.64(3) degrees, V = 2843(4) Å(3), Z = 2, R = 0.0281. The chloro functions in 1-6 remain reactive, demonstrated by the isolation of the trifluoroacetate derivatives of 1 and 2. Treatment of 1 or 2 with 2 equiv of NaOCOCF(3) gives [{{(t-Bu)NSiMe(2)SiMe(2)N(t-Bu)}Ln(&mgr;-OCOCF(3))(THF)}(2)] (7, Ln = Nd; 8, Ln = Gd). The structure of 8 was determined by a single-crystal X-ray diffraction analysis. Crystal data for 8: triclinic, P&onemacr;, a = 11.045(2) Å, b = 16.120(3) Å, c = 16.949(3) Å, alpha = 66.17(3) degrees, beta = 85.51(3) degrees, gamma = 78.27(3) degrees, V = 2702.9(9) Å(3), Z = 2, R = 0.0311. The structure of 8 shows the trifluoroacetate group adopting a bridging bidentate mode of coordination.
The reaction of [(eta(5)-C(5)Me(5))ZrF(3)] and [(eta(5)-C(5)Me(5))HfF(3)] with Me(3)SiOCOCF(3) yields the dinuclear complexes [{(eta(5)-C(5)Me(5))ZrF(OCOCF(3))(2)}(2)] (1) and [{(eta(5)-C(5)Me(5))HfF(OCOCF(3))(2)}(2)] (2), regardless of the molar ratio employed. [(eta(5)-C(5)Me(5))(2)ZrF(2)] reacts with 1 and 2 equiv of Me(3)SiOCOCF(3) to form the mononuclear compounds [(eta(5)-C(5)Me(5))(2)Zr(OCOCF(3))(2)] (3) and [(eta(5)-C(5)Me(5))(2)ZrF(OCOCF(3))] (4), respectively. The molecular structures of 1 and 3 have been determined by single-crystal X-ray analysis: 1, triclinic, P&onemacr;, a = 9.508(3) Å, b = 11.002(4) Å, c = 17.528(3) Å, alpha = 78.55(4), beta = 76.80(2), gamma = 87.51(2) degrees, V = 1750(1) Å(3), Z = 2, R = 0.0378; 3, monoclinic, C2/c, a = 18.553(4) Å, b = 9.110(2) Å, c = 16.323(3) Å, beta = 114.88(3) degrees, V = 2503(1) Å(3), Z = 4, R = 0.0457. Compound 1 shows bridging bidentate and chelating carboxylate ligands as well as bridging fluorine atoms. The zirconium atoms are seven coordinated and have an 18-electron configuration. X-ray studies of 3 reveal two structural components where the carboxylate ligands coordinate in a monodentate (major component) and a chelating manner (minor component).
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Tetrameric [{(C(5)Me(5))MF(3)}(4)] (M = Zr, Hf) react smoothly with Me(3)SiCl in CH(2)Cl(2) at room temperature to give [{(C(5)Me(5))ZrF(2)Cl}(4)] (1) and [{(C(5)Me(5))HfF(2)Cl}(4)] (2), respectively, in high yield. Treatment of [{(C(5)Me(5))MF(3)}(4)] (M = Zr, Hf) with Me(2)AlCl in toluene gives mixtures of 1 and [(C(5)Me(5))(4)Zr(4)(&mgr;-F)(2)(&mgr;-F(2))(2)(&mgr;-Cl)(2)Cl(4)] (3), and 2 and [(C(5)Me(5))(4)Hf(4)(&mgr;-F)(2)(&mgr;-F(2))(2)(&mgr;-Cl)(2)Cl(4)] (4), respectively, in an approximately 1:1 molar ratio. Metallocene type complexes [(C(5)Me(4)Et)(2)ZrCl(2)] and [(C(5)Me(5))(2)HfCl(2)] react with 1 equiv of Me(3)SnF to give [(C(5)Me(4)Et)(2)ZrClF] (5) and [(C(5)Me(5))(2)HfClF] (6), respectively. The complexes 1-6 were characterized by spectroscopic methods ((1)H and (19)F NMR and mass spectroscopy). The solid state structures of 1, 3, and 5 were determined by single-crystal X-ray diffraction analyses.