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Minghuey Shieh Horng-Sun Chen Huey-Yea Yang Chuen-Her Ueng 《Angewandte Chemie (International ed. in English)》1999,38(9):1252-1254
The first Te–Mn–CO clusters were obtained by the thermal reaction of K2TeO3 with [Mn2(CO)10] in MeOH. The basicity of the μ4-Te ligand in the octahedral cluster anion [(μ4-Te)2Mn4(CO)12]2− is demonstrated by its binding to the fragment [(TeMe2)Mn(CO)4]+ in an axial fashion to afford the novel cluster 1 . 相似文献
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Rodrigo J. Lobo‐Lapidus Bruce C. Gates 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(37):11386-11398
Two carbonyl complexes of rhenium, [HRe(CO)5] and [CH3Re(CO)5], were used to probe surface sites of TiO2 (anatase). These complexes were adsorbed from the gas phase onto anatase powder that had been treated in flowing O2 or under vacuum to vary the density of surface OH sites. Infrared (IR) spectra demonstrate the variation in the number of sites, including Ti+3? OH and Ti+4? OH. IR and extended X‐ray absorption fine structure (EXAFS) spectra show that chemisorption of the rhenium complexes led to their decarbonylation, with formation of surface‐bound rhenium tricarbonyls, when [HRe(CO)5] was adsorbed, or rhenium tetracarbonyls, when [CH3Re(CO)5] was adsorbed. These reactions were accompanied by the formation of water and surface carbonates and removal of terminal hydroxyl groups associated with Ti+3 and Ti+4 ions on the anatase. Data characterizing the samples after adsorption of [HRe(CO)5] or [CH3Re(CO)5] determined a ranking of the reactivity of the surface OH sites, with the Ti+3? OH groups being the more reactive towards the rhenium complexes but the less likely to be dehydroxylated. The two rhenium pentacarbonyl probes provided complementary information, suggesting that the carbonate species originate from carbonyl ligands initially bonded to the rhenium and from hydroxyl groups of the titania surface, with the reaction leading to the formation of water and bridging hydroxyl groups on the titania. The results illustrate the value of using a family of organometallic complexes as probes of oxide surface sites. 相似文献
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Mirka Bergamo Tiziana Beringhelli Giuseppe D'Alfonso Pierluigi Mercandelli Massimo Moret Angelo Sironi 《Angewandte Chemie (International ed. in English)》1998,37(15):2128-2131
The first five-membered rings of metal atoms connected by M–M or M-H-M bonds only have been obtained by a Re2+Re3 condensation in which a polyhydride acts as a bridging bidentate ligand toward a coordinatively unsaturated fragment (see scheme below). In spite of the octahedral coordination of the Re centers, the Re5 rings display conformations (twisted and envelope) comparable with those observed for organic five-membered rings of tetrahedral carbon atoms. 相似文献
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Hans‐Christian Bttcher Marion Graf Kurt Merzweiler Christoph Wagner 《无机化学与普通化学杂志》2001,627(5):903-908
Heterobinuclear Complexes: Synthesis and X‐ray Crystal Structures of [RuRh(μ‐CO)(CO)4(μ‐PtBu2)(tBu2PH)], [RuRh(μ‐CO)(CO)3(μ‐PtBu2)(μ‐Ph2PCH2PPh2)], and [CoRh(CO)4(μ‐H)(μ‐PtBu2)(tBu2PH)] [Ru3Rh(CO)7(μ3‐H)(μ‐PtBu2)2(tBu2PH)(μ‐Cl)2] ( 2 ) yields by cluster degradation under CO pressure as main product the heterobinuclear complex [RuRh(μ‐CO)(CO)4(μ‐PtBu2)(tBu2PH)] ( 4 ). The compound crystallizes in the orthorhombic space group Pcab with a = 15.6802(15), b = 28.953(3), c = 11.8419(19) Å and V = 5376.2(11) Å3. The reaction of 4 with dppm (Ph2PCH2PPh2) in THF at room temperature affords in good yields [RuRh(μ‐CO)(CO)3(μ‐PtBu2)(μ‐dppm)] ( 7 ). 7 crystallizes in the triclinic space group P 1 with a = 9.7503(19), b = 13.399(3), c = 15.823(3) Å and V = 1854.6 Å3. Moreover single crystals of [CoRh(CO)4(μ‐H)(μ‐PtBu2)(tBu2PH)] ( 9 ) could be obtained and the single‐crystal X‐ray structure analysis revealed that 9 crystallizes in the monoclinic space group P21/a with a = 11.611(2), b = 13.333(2), c = 18.186(3) Å and V = 2693.0(8) Å3. 相似文献
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Concurrent Stabilization of π‐Donor and π‐Acceptor Ligands in Aromatized and Dearomatized Pincer [(PNN)Re(CO)(O)2] Complexes 下载免费PDF全文
Michael G. Mazzotta Dr. Kothanda Rama Pichaandi Dr. Phillip E. Fanwick Prof. Dr. Mahdi M. Abu‐Omar 《Angewandte Chemie (International ed. in English)》2014,53(32):8320-8322
Aromatized cationic [(PNN)Re(π acid)(O)2]+ ( 1 ) and dearomatized neutral [(PNN*)Re(π acid)(O)2] ( 2 ) complexes (where π acid=CO ( a ), tBuNC ( b ), or (2,6‐Me2)PhNC ( c )), possessing both π‐donor and π‐acceptor ligands, have been synthesized and fully characterized. Reaction of [(PNN)Re(O)2]+ ( 4 ) with lithiumhexamethyldisilazide (LiHMDS) yield the dearomatized [(PNN*)Re(O)2] ( 3 ). Complexes 1 and 2 are prepared from the reaction of 4 and 3 , respectively, with CO or isocyanides. Single‐crystal X‐ray structures of 1 a and 1 b show the expected trans‐dioxo structure, in which the oxo ligands occupy the axial positions and the π‐acidic ligand occupies the equatorial plane in an overall octahedral geometry about the rhenium(V) center. DFT studies revealed the stability of complexes 1 and 2 arises from a π‐backbonding interaction between the dxy orbital of rhenium, the π orbital of the oxo ligands, and the π* orbital of CO/isocyanide. 相似文献
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Azido Derivatives of the Pentamethylcyclopentadienyl Vanadium(IV)-Fragment. Molecular Structures of the Binuclear Complexes [Cp*VCl(N3)(μ-N3)]2 and [Cp*V(N3)2(μ-N3)]2 The stepwise reaction of Cp*VCl3 with excess trimethylsilyl azide (Me3Si–N3) in solution leads to the paramagnetic, azido-bridged complexes [Cp*VCl2(μ-N3)]2 ( 3 ), [Cp*VCl(N3)(μ-N3)]2 ( 4 ) and [Cp*V(N3)2(μ-N3)]2 ( 5 ) which were characterized by their IR and mass spectra. The azide-rich binuclear complex 5 is also formed if a pentane solution of Cp*V(CO)4 is stirred in the presence of excess Me3Si–N3 in an open vessel. According to the X-ray structure analyses both 4 and 5 are centrosymmetric molecules with a planar V(N)2V four-membered ring. In the absence of free trimethylsilyl azide, solutions of 3 – 5 lose dinitrogen slowly; in the presence of traces of air, 5 is thereby converted to the diamagnetic, oxo-bridged complex [Cp*V(O)(N3)]2(μ-O) ( 6 ). 相似文献