Reaction patterns of ‘tetraferrio-azaallenium’, [(OC)3Cp2Fe2(μ4-CNC)Fe2Cp2(CO)3]+, and its ‘activated cyanide’-precursor (μ-phthalimidocarbyne)tricarbonyldicyclopentadienyldiiron(1+)

Some ruthenium complexes containing cyanocarbon ligands: syntheses, structures and extent of electronic communication in binuclear systems

“…In addition to the molecular ion (m/z 802) and a fragment ion formed by loss of the cyanocarbon ligand, the ES mass spectrum of 8 also featured an isotopic envelope arising from the binuclear complex 9. As detailed in Section 7, the IR spectra of these complexes contain between one and four m (CN) bands, in contrast to the free [C 3 (CN) 5 ] À anion, which has only one at 2199 cm À1 .…”

“…The bright orange pentacyanopropenide derivative Ru{NCC(CN)C(CN)‚C(CN) 2 }(PPh 3 ) 2 Cp (6; Scheme 1) was obtained from equivalent amounts of RuCl (PPh 3 ) 2 Cp and [NMe 4 ][C 3 (CN) 5 ] via a minor modification of the method previously described [18]. Use of two equivalents of RuCl(PPh 3 ) 2 Cp with NH 4 PF 6 as an additional halide abstracting reagent afforded dark purple [{Ru(PPh 3 ) 2 Cp} 2 {l-C 3 (CN) 5 }]PF 6 (7), characterised by elemental analysis and from its ES mass spectrum, which contained ions at m/z 1548 [{Ru(PPh 3 ) 2 Cp} 2 C 3 -(CN) 5 ] + ("M + ), 1286 ([M À PPh 3 ] + ) and 1024 ([M À 2PPh 3 ] + ).…”

“…Further consideration of the differences in redox potentials in terms of the bridging group X in the ligands [NC-X-CN] À shows a decrease in the order X = H (3; 500 mV) > C 3 (CN) 5 (300 for 7, 200 for 9) > CN (5;230) > N (180 [23]). Corresponding values for K C for 3 and 5 are 2.8 · 10 8 and 7.7 · 10 3 , respectively.…”

“…A great deal of contemporary interest is centred around the use of CN ligands in the design and control of molecular shape, the cyanide-isocyanide isomerism and electron-transfer processes [4,5]. Commonly used metal-containing building blocks include the Fe(dppe)Cp and Ru(PPh 3 ) 2 Cp groups, with one of the first reports being given by Davies and coworkers [6].…”

“…doi:10.1016/j.jorganchem.2004.07.030 dinitriles [12,13], while cyano-carbon and -nitrogen anions have proved to be versatile constituents of electroand magnetically active materials [14]. The structure and electrochemical properties of the anionic complex [W{NCC (CN)C(CN)C(CN) 2 }(CO) 5 ] À have been described [15] and more recently, metal-metal interactions through the CH 2 (L) 2 Cp]PF 6 (M = Fe, Ru; L = PPh 3 , dppe/2) have been claimed [16]. VahrenkampÕs perspective [2] allows access to many relevant reviews and papers.…”