Hydrido complexes of ruthenium with carborane ligands

Abstract

Hydride Complexes of Ru with Carborane Ligands Co(III), Cu(I) formulation would expect a yellow, diamagnetic product similar to the Cu(fdpp)I material.The UV-visible spectra, Table IV, demonstrate the electronic changes that have occurred in the (cdpp)+ fragment of the Cu(cdpp)Cl2. In the spectrum of Cu(cdpp)Cl2 there are no UV-visible absorptions which can clearly be attributed to the ligand [cdpp]+. In contrast the high-energy portion of the UV-visible spectrum for [Co(cdpp)Cl2]Cl matches the UV-visible spectrum of [cdpp]PF6 exactly.A more acceptable valence assignment is Con/Cun. This assignment accounts for the changes in the ligand part of the UV-visible spectrum and the paramagnetism of the compound.Since this material would have two paramagnetic centers, it could display magnetic concentration effects such as fielddependent paramagnetism. Nevertheless, magnetic concentration effects are complex, and more extensive study is needed before any realistic assignment can be made for this material. Conclusion1,1 ,-Bis(diphenylphosphino)cobaltocenium hexafluoro-

Selenium and tellurium derivatives of a monocarbon platinacarbaborane complex †

“…Many such charge-compensated metallacarbaboranes are known. 9, 12 The molecule 4 is shown in Fig. 5 and selected internuclear distances and angles are listed in Table 4.…”

Facile method for the synthesis of ruthenacarboranes, diamagnetic 3,3-[Ph2P(CH2)nPPh2]-3-H-3-Cl-closo-3,1,2-RuC2B9H11 (n = 3 or 4) and paramagnetic 3,3-[Ph2P(CH2)nPPh2]-3-Cl-closo-3,1,2-RuC2B9H11 (n = 2 or 3), as efficient initiators of controlled radical polymerization of vinyl monomers

“…The starting closo complex 3 has been synthesized ear lier by two methods: (1) according to a scheme 8 (5) in an Et 2 O-THF mixture 10 or benzene at 22 °C. 5 In the present study, we substan tially modified the latter method by using the one pot thermal reaction of complex 4 with an insignificant excess of salt 5 in benzene to prepare closo complex 3 (Scheme 2).…”

“…In the former case, the replacement affords exclusively the 18 electron complex 3,3 (Ph 2 P(CH 2 ) 4 PPh 2 ) 3 H 3 Cl closo 3,1,2 RuC 2 B 9 H 11 (6) in 86% yield. In the latter case, the reac tion produces a mixture of the 18 and 17 electron com plexes 3,3 (Ph 2 P(CH 2 ) 3 PPh 2 ) 3 H 3 Cl closo 3,1,2 RuC 2 B 9 H 11 (7) and 3,3 (Ph 2 P(CH 2 ) 3 PPh 2 ) 3 Cl closo 3,1,2 RuC 2 B 9 H 11 (8) in a ratio of 6.7 : 1 in a total yield of 90% (Scheme 3). Earlier, we have synthesized 2 an analo gous mixture of complexes 7 and 8 by the reaction of exo nido complex 1 with dppp, and this mixture has been separated into individual compounds by TLC.…”

Synthesis, Characterization, and Molecular Structure of the First closo-Hydrido Complexes of Osmium with Carborane Ligands: closo-3,3-(PPh3)2-3-H-3-Cl-3,1,2-OsC2B9H11 and closo-3,3-(PPh3)2-3,3-H2-1,2-Me2-3,1,2-OsC2B9H9

“…Hydridometallacarborane clusters of closo and exo-nido types have played an important role in the development of metallacarborane chemistry and since the discovery of their catalytic activity have found widespread use as catalyst precursors in numerous organic processes. , Although now the variety of closo -hydridometallacarboranes of platinum group metals derived from nido -C 2 B 9 H 12 2- is very extensive, − examples of closo -hydridoosmacarboranes are still lacking. This is particularly surprising taking into account the known ability of osmium to form stable closo -osmaborane clusters 9 and also in view of well-documented chemistry of related closo -hydridoruthenacarboranes. − A successful synthesis of the latter by the oxidative addition of 7,8- and 7,9-C 2 B 9 H 12 - to coordinatively unsaturated Ru(II) species 6,7 or by thermal rearrangement of some exo-nido -ruthenacarboranes 8 prompted us to examine these possible routes for the preparation of 12-vertex osmium congeners. We now report the synthesis of closo -3,3-(PPh 3 ) 2 -3-H-3-X-1,2-R 2 -3,1,2-OsC 2 B 9 H 9 ( 1a , R = H, X = Cl; 1b , R = X = H; 1c , R = Me, X = H) and X-ray structural characterization of two of them, namely 1a , c .…”

“…Hydridometallacarborane clusters of closo and exonido types have played an important role in the development of metallacarborane chemistry 1 and since the discovery of their catalytic activity 2 have found widespread use as catalyst precursors in numerous organic processes. 3,4 Although now the variety of closo-hydridometallacarboranes of platinum group metals derived from nido-C 2 B 9 H 12 2is very extensive, [5][6][7][8] examples of closo-hydridoosmacarboranes are still lacking. This is particularly surprising taking into account the known ability of osmium to form stable closo-osmaborane clusters 9 and also in view of well-documented chemistry of related closo-hydridoruthenacarboranes.…”