Intermetallic transfer of unsymmetrical borylene fragments: isolation of the second early-transition-metal terminal borylene complex and other rare species
作者:Bret B. Macha、Debabrata Dhara、Krzysztof Radacki、Rian D. Dewhurst、Holger Braunschweig
DOI:10.1039/d0dt03557b
日期:——
effectively transfer the borylene ligand to other transition metal complexes by replacing one or two carbonyl ligands upon irradiation of the reaction mixture with UV light. This borylenetransfer reaction led to the formation of new terminal and bridging borylenecomplexes which cannot be formed by the corresponding salt elimination reactions, including a rare example of a bis(terminal borylene) complex
Metal—ligand bonding in LM(CO)5 complexes (L = NMe3, PMe3, PCl3, PBr3 or AsMe3; M = Cr, Mo or W) from dielectric, electro-optic and spectroscopic evidence
作者:M.S. Davies、R.K. Pierens、M.J. Aroney
DOI:10.1016/0022-328x(93)80466-o
日期:1993.10
and 13C NMR spectral shifts of LM(CO)5 complexes where L = NMe3, PMe3, PCl3, PBr3 or AsMe3 and M = Cr, Mo or W. Analysis of the polarisability anisotropies of the complexes provides direct, experimentally based evidence indicating a substantial π-component in the phosphorus—metal and arsenic—metal bonding in P(As)Me3M(CO)5 within a highly polarisable P(As)M(trans)CO delocalised π-electron system. The
已对LM(CO)5配合物的电偶极矩,光学极化率各向异性(通过电双折射测量),红外羰基拉伸频率和13 C NMR光谱位移进行了比较研究,其中L = NMe 3,PMe 3,PCl 3,PBr 3或AsMe 3,M = Cr,Mo或W。对络合物的极化率各向异性的分析提供了直接的,基于实验的证据,表明P(As)中磷-金属和砷-金属键中存在大量的π成分。在高度极化的P(As)M(反式)中的Me 3 M(CO)5CO离域π电子系统。LMπ键似乎不受L从PMe 3到AsMe 3的变化或三价铬中M的变化的显着影响。结果表明,磷配体中的负电性卤素取代基增强了磷与金属之间的π键结合以及沿PM(trans)CO键的电子离域作用。得出的结论与红外和13 C NMR光谱和偶极矩数据的解释结果基本一致。
Photochemical Generation of Dihydrogen Complexes of Chromium and Tungsten
作者:Steven L. Matthews、D. Michael Heinekey
DOI:10.1021/ja057912r
日期:2006.3.1
of solutions of M(CO)(6) (M = Cr, W) at low temperature in the presence of hydrogen gas affords Cr(CO)(5)(H(2)) (1) and W(CO)(5)(H(2)) (2). Complexes 1 and 2 are characterized as dihydrogen complexes based on short T(1) values for the hydride resonances and the observation of a large HD coupling in the HD derivatives. Irradiation of a phosphine-substituted derivative (PMe(3))Cr(CO)(5) in the presence
Electron paramagnetic resonance studies of radical pairs [M(CO) ? 5 ]2(M = Cr, Mo, W) trapped in single crystals of PPh + 4 HM(CO) ? 5
作者:Rosemary C. Hynes、Keith F. Preston、Jerry J. Springs、John S. Tse、Antony J. Williams
DOI:10.1039/ft9918703121
日期:——
γ-Irradiated singlecrystals of PPh+4HM(CO)–5(M = Cr, Mo, W) exhibit powerful EPR spectra due to two distinct interacting pairs of M(CO)–5 radicals. g- and fine-structure (D) matrices were determined from measurements at 77 K of EPR spectra obtained as a function of angle in the ac and aa′ planes of crystallographically aligned singlecrystals of the Mo and W compounds. The data are compared with those
Main Group Compounds as Amphoteric Ligands to Transition Metals. Synthesis and Molecular Structure of Cr(CO)<sub>5</sub>[PPh<sub>2</sub>CH<sub>2</sub>Ga(CH<sub>2</sub>CMe<sub>3</sub>)<sub>2</sub>·NMe<sub>3</sub>]
作者:O. T. Beachley,、Michael A. Banks、John P. Kopasz、Robin D. Rogers
DOI:10.1021/om960547f
日期:1996.11.26
NEt4MT(CO)5Cl (MT = Cr, Mo, W) to form products of the type NEt4MT(CO)5[PPh2MR2Cl]. All new compounds were characterized by their physical properties, C and H analyses, and 1H and 31P NMR and IR spectral properties. The identity of NEt4Cr(CO)5[PPh2In(CH2SiMe3)2Cl] was further confirmed by the subsequent identification of products from reactions with anhydrous HCl and with MeI. In addition, Cr(CO)5[PPh