Terminal Acetylenes React to Increase Unsaturation in [(tBu2PCH2SiMe2)2N]Re(H)4
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- 作者：Oleg V. Ozerov ; Lori A. Watson ; Maren Pink ; Mu-Hyun Baik ; and Kenneth G. Caulton
- 刊名：Organometallics
- 出版年：2004
- 出版时间：October 11, 2004
- 年：2004
- 卷：23
- 期：21
- 页码：4934 - 4943
- 全文大小：245K
- 年卷期：v.23,no.21(October 11, 2004)
- ISSN：1520-6041
文摘
(PNPtBu)Re(H)4, where PNPtBu is (tBu2PCH2SiMe2)2N, reacts at 23 
C with RC
CH (R =tBu, SiMe3, Ph) to give first H2 and mirror-symmetric (PNPtBu)ReH3(CCR), then H2 and C2
symmetric (PNPtBu)Re(CCR)2. The diacetylide compounds show temperature-independentparamagnetism and 13C and 31P chemical shifts far beyond their normal values for other(PNPtBu)ReXn compounds. Single-crystal X-ray diffraction shows very similar structures forthe cases R = Ph and R = SiMe3, each having an approximately C2v geometry with equivalentacetylides with 
C-Re-C approximately 108. No hydride or H2 ligands are detected infinal difference Fourier maps. DFT(B3PW91) calculations give minimum energy geometriesof these species, of their products upon adding H2, and of mechanistically significantanalogues [(H2PCH2SiH2)2N]ReHnR'mH2-m, with n = 0, 2, m = 1, 2, and R' = H or Ph. Thesecalculated geometries, when compared to those from X-ray diffraction, indicate that theisolated compounds have no hydride or H2 ligands and are thus (PNP)ReIII(CCR)2, makingthem more unsaturated than the reagent (PNP)ReV(H)4 by two electrons. Triplet stategeometries of (PNP)ReXY are calculated and analyzed, as are their frontier orbitals.
C with RCCH (R =tBu, SiMe3, Ph) to give first H2 and mirror-symmetric (PNPtBu)ReH3(CCR), then H2 and C2symmetric (PNPtBu)Re(CCR)2. The diacetylide compounds show temperature-independentparamagnetism and 13C and 31P chemical shifts far beyond their normal values for other(PNPtBu)ReXn compounds. Single-crystal X-ray diffraction shows very similar structures forthe cases R = Ph and R = SiMe3, each having an approximately C2v geometry with equivalentacetylides with C-Re-C approximately 108. No hydride or H2 ligands are detected infinal difference Fourier maps. DFT(B3PW91) calculations give minimum energy geometriesof these species, of their products upon adding H2, and of mechanistically significantanalogues [(H2PCH2SiH2)2N]ReHnR'mH2-m, with n = 0, 2, m = 1, 2, and R' = H or Ph. Thesecalculated geometries, when compared to those from X-ray diffraction, indicate that theisolated compounds have no hydride or H2 ligands and are thus (PNP)ReIII(CCR)2, makingthem more unsaturated than the reagent (PNP)ReV(H)4 by two electrons. Triplet stategeometries of (PNP)ReXY are calculated and analyzed, as are their frontier orbitals.