Spin delocalisation and the geometry of redox-active cyanomanganesecarbonyl ligands in heteropolynuclear complexes of rhodium(I)

Metal–metal charge transfer and solvatochromism in cyanomanganese carbonyl complexes of ruthenium and osmium

“…The osmium-containing trication 12 3+ , with the Os III (NH 3 ) 5 fragment a weaker acceptor than Ru III (NH 3 ) 5 , displays carbonyl bands with the more usual relative intensities (Table 1) {and with m(CN), at 2074 cm −1 , shifted less to lower wavenumber than in the ruthenium analogue 6 3+ (2045 cm −1 )}, consistent with this explanation. and (NC)Mn(CO) 2 {P(OEt) 3 }(dppm), 6-7, 23 the geometry around manganese is essentially octahedral in both 10 3+ and 11 3+ ; the largest angular distortions from regular geometry are due to the small bite of the dppm chelate which leads to P dppm -Mn-P dppm angles of less than 74 • . In 10 3+ the carbonyl is trans to the cyanide bridge and the four phosphorus atoms of the two dppm ligands occupy the equatorial positions; in 11 3+ the CO ligands are mutually trans, with the cyanide bridge trans to a phosphorus atom of the bidentate dppm ligand.…”

Coordination chemistry of a bulky redox-active cyanomanganese carbonyl ligand: N-bound tetrahedral complexes of 3d metals

“…Cyanide-bridged complexes with the Mn I (µ-CN)M core, systematically constructed by attaching redox-active, N-donor manganese() 'ligands' such as trans-[Mn(CN)(CO)(dppm) 2 ], 1 cis-and trans-[Mn(CN)(CO) 2 {P(OR) 3 }(dppm)] (R = Et or Ph) 2 and [Mn(CN)(PR 3 )(NO)(η-C 5 H 4 Me)] (R = Ph or OPh) 3 to a second metal centre, M, show electron transfer behaviour and other electronic properties 4, 5 which are influenced by the coordination geometry and ancillary ligands at both Mn() and M. To date, most of our studies have involved transition metals, M, in low oxidation states, such as linear gold(), 6 square planar Rh(), 7 tetrahedral Fe(Ϫ), 8 etc. However, preliminary studies showed 9 that cyanomanganese ligands could also coordinate to first row transition metal dihalides MCl 2 (M = Mn, Co and Ni) to give bi-and poly-nuclear species in which an organometallic fragment, i.e.…”

Tetrakis(tert-butyl isocyanide-2κC)dichloro-1κCl,3κCl-di-μ-cyano-1κN:2κC;2κC:3κN-bis[1,3(η4)-cycloocta-1,5-diene]dirhodium(I)ruthenium(II)

“…Three-dimensional arrangements of rhodium ions bridged by cyanide ligands have been described in terms of a cuboidal structure (Klausmeyer et al, 1998) and as an oligomer with seven rhodium centers, which is best described as a cube with one missing corner (Contakes et al, 1998). All other structures reported so far are linear coordination complexes, being either discrete dinuclear (Atkinson et al, 1993;Bezrukova et al, 1993) or trinuclear (Deeming et al, 1988;Atkinson et al, 1993) compounds. There have also been reports of coordination polymers, which were synthesized from rhodium carboxylates and hexacyanoferrate(II) (Kim et al, 2001), hexacyanocobaltate(III) (Lu et al, 1996) or [( 5 -C 5 H 5 )Ir(CO) 3 ] (Contakes et al, 2000).…”