15  Iron, cobalt and nickel

Luminescent coordination polymers with extended Au(I)–Ag(I) interactions supported by a pyridyl-substituted NHC ligand

“…Metathesis to the analogous Au(I)-species [Au(CH 3 impy) 2 ]PF 6 , 2, was accomplished using a simple carbene transfer reaction with Au(tht)Cl in either CH 2 Cl 2 or CH 3 CN. Further treatment of 2 with excess AgBF 4 in acetonitrile, benzonitrile and benzylnitrile coordinates a metal to the uncoordinated pyridyl moieties producing the polymeric species {[AuAg(CH 3 impy) 2 (L)]-(BF 4 ) 2 } n , (L = CH 3 CN,3; L = C 6 H 5 CN, 4; L = C 6 H 5 CH 5). In these polymers the Au(I) centers remain bound to two carbene moieties while the Ag(I) centers are coordinated to two alternating pyridyl groups and a solvent molecule (L).…”

“…These non-bonding interactions are sufficiently strong to overcome the anticipated Coloumbic repulsion between like-charged metals, and extensive networks of cationic complexes can be formed in the solid-state [4]. Short aurophilic Au(I)-Au(I) interactions are also achievable through aggregation of linear, two-coordinate gold monomers in the solid-state or by the incorporation of bridging ligands [5]. Several theories have been advanced to rationalize these interactions, prominent among which are dispersion forces and relativistic effects [6].…”

Di- and tri-nuclear molybdenum–palladium complexes bearing strong π-acceptor “P–N–P” ligands, MeN{P(OR)2}2 (R=CH2CF3 or Ph)

“…This is reflected in the Mo-Pd distance [2.63(1) Å ] which is 0.23 Å shorter than that for 3a [2.86 (1) Å ] having a Mo-Pd single bond and also 0.20-0.29 Å shorter than that found in several Mo-Pd heteronuclear complexes containing dppm and other ligands (Table 8). Casey et al [38] have concluded that there is a double bond between two Re atoms in [Cp*(CO) 2 Re@Re(CO) 2 The description of bonding of semi-bridging carbonyls to transition metals has been the subject of several investigations [39][40][41][42][43][44]. Following the approach of Crabtree and Lavin [43], the various parameters Ôa, b, c, d, e, h and WÕ for the semi-bridging carbonyls in 5b and 6a are listed in Table 9.…”

Chlorocarbonyl ruthenium(II) complexes of tripodal triphos {MeC(CH2PPh2)3}: Synthesis, characterization and catalytic applications in transfer hydrogenation of carbonyl compounds

“…Tridentate tripodal phosphines are recognized as one of the most important classes of ligands having widespread applications in coordination chemistry [1][2][3][4][5][6][7][8][9][10]. Such ligands provide an important advantage over monodentate phosphines with respect to greater control of the coordination number, stoichiometry and stereochemistry of their complexes [11].…”