Synthesis and Reactivity of a Zwitterionic Palladium Allyl Complex Supported by a Perchlorinated Carboranyl Phosphine

Abstract

A zwitterionic palladium complex of a phosphine bearing a perchlorinated carba-closo-dodecaborate anion as a ligand substituent is reported. A single-crystal X-ray diffraction study reveals that, in the solid state, one of the chlorides of the carborane cage occupies a coordination site of the square-planar complex. However, in solution, the P-carborane bond of the ligand is rapidly rotating at temperatures as low as -90 °C, which demonstrates the carborane substituent's weak coordinative ability even though this anion is covalently linked to the phosphine ligand. The complex is thermally stable and catalyzes the vinyl addition polymerization of norbornene.

Ethylene Oligomerization and Polymerization by Palladium(II) Methyl Complexes Supported by Phosphines Bearing a Perchlorinated 10-Vertex closo-Carborane Anion Substituent

“…The B – Cl bond lengths for the bound B–Cl units ([Li­(THF) 3 ]­[ 5 ]: 1.790(2) Å, 7 – CH 3 CN : 1.795(2) Å; 8 : 1.800(2) Å) are ca. 0.03 Å longer than average lengths of the terminal B–Cl bonds in the ortho layer of the carboranyl unit ([Li­(THF) 3 ]­[ 5 ]: 1.761[1] Å, 7 – CH 3 CN : 1.768[1] Å; 8 : 1.764[4] Å), similar to what is observed for C . The 5-membered Pd–P–C–B–Cl chelate ring adopts an envelope conformation in 7 and a planar conformation in [Li­(THF) 3 ]­[ 5 ] and 8 .…”

“…PR 2 CB 9 Cl 9 – ligands 1 – 3 were synthesized as the Li­(THF) x salts ( x = 2–4) following the procedure developed earlier for the 12-vertex analogue [Li­(THF) 3 ]­[P i Pr 2 CB 11 Cl 11 ] (Scheme ). , C-Lithiation of HCB 9 Cl 9 – followed by addition of the appropriate R 2 PCl electrophile affords [Li­(THF) x ]­[ 1 – 3 ] in >90% yield.…”

Intramolecular charge transfer induced emission from triphenylamine-o-carborane dyads

“…In the past decades, carborane-based materials have attracted particular interest in boron neutron capture therapy, 1-3 heat-resistant agents, 4,5 and coordination/ organo-metallic chemistry as ligands. [6][7][8][9][10][11] Although carboraneorganic materials have been developed as novel aggregationinduced-emission (AIE)-active luminogens, their emissive mechanisms still remain unclear to date. The reasons are mainly because the electron-decient parent carborane clusters show little or no absorption at >250 nm, nor any emission, and their emissions were seriously inuenced by the external stimuli.…”

Ru(ii) and Ir(iii) phenanthroline-based photosensitisers bearingo-carborane: PDT agents with boron carriers for potential BNCT

“…66 Since the first works from Lee et al 67 and Yan et al 68 of carborane iridium(III) complexes, many different iridiumcarborane systems have been reported with diverse uses as chemosensors, or for bioimaging, among others. [69][70][71][72][73][74][75][76] Less developed are those metal-carborane systems peripherally bonded to other metal centres such as gold, 77,78 silver, 79 palladium, 80 or copper. 81 While examples of ruthenacarboranes are found in the literature, 82 strikingly there are no trisbidentate Ru(II)-carborane metal complexes reported.…”