Dinuclear carbonyl complexes

Dinuclear carbonyl complexes, with copper, 2, 187-188 Dinuclear chromium(III) complexes, with halides, alkyls, aryls, 5, 317... 

The primary photochemical reaction of the [MM (CO)i0] (M, M =Mn, Re) complexes in solution has been shown to result in (1) homolytic fission of the metal-metal cr-bond to form M(CO)s radicals, (2) dissociation of a CO ligand to form [MM (CO)9], and (3) non-dissociative relaxation to the electronic ground state [86]. Similar behaviour is shown by other dinuclear carbonyl complexes [87]. 

An unexpected reaction was reported to occur on treatment of [Cu(dcmpz)] , 12, with CO in pyridine (27). The dinuclear monocarbonyl complex Cu2(dcmpz)2(py)2(CO), 37, was obtained and its X-ray crystal structure was determined. An analogy was drawn between the CO-hemocyanin adduct and the dinuclear carbonyl Complex 37. The observed stoichiometry of CO bonding... 

The alkoxocarbonyl complexes described above are thought to be the products of the nucleophilic attack of MeOH or EtOH on the dinuclear carbonyl Complexs 55 and 71, which were previously oxidized by iodine, as the latter complex are indefinitely stable in alcohols (82). 

Dinuclear iron carbonyl complexes with nitrogen containing bridges. A. N. Nesmeyanov, M. I. Rybinskaya and L. V, Rybin, Russ. Chem. Rev. (Engl. Transl.), 1979,48, 213-227 (123). 

The simplest transition metal carbonyls are mononuclear of the type M(CO)x, in other words those with only one metal atom. They are hydrophobic but soluble to some extent in nonpolar liquids, such as n-butane or propane. The dinuclear carbonyls are more complex but have the same general characteristics as the mononuclear carbonyls. The carbonyls, which are or could be used in CVD, are listed in Table 3.4 with some of their properties. 

The first homoleptic, dinuclear platinum(I) carbonyl complex [Pt2(CO)6]2+ has been prepared by dissolving Pt02 in concentrated sulfuric acid under a CO atmosphere.92,93 The structure is rigid on the NMR time scale at room temperature. DFT studies suggested a staggered structure for the dimer.92,93... 

Dinuclear Ru and Os complexes containirm halo bridges include a number of fluoro carbonyl complexes, described in the last section. The reactions between anhydrous HF and [MH2(CO)2(PPh3)2] (M = Ru, Os) produce cix,cA,tra i-[MF2(CO)2(PPh3)2], but when the precursor is [MH2(CO)(PPh3)3], the dinuclear complexes [M2(CO)2(PPh3)4(/u-F)3]" result. Initially, these form as the [Hp2] salts, but are better isolated as the air-stable [BPh4] salts. " ... 

Numerous dinucleating macrocyclic and macrobicyclic ligands have been synthesized, in particular by the versatile amine + carbonyl — imine reaction they form dinuclear metal complexes as well as cascade complexes with bridging groups [2.58-2.63, 3.24-3.27, 4.1-4.4], for instance in dicobalt complexes that are oxygen carriers [3.26]. 

The reaction of RhHL3 (L = P(iso-Pr)3) with CO was thought to give Complex 7. Instead, the product formed from the reaction in dry hexane under a CO atmosphere was a binuclear Rh(0) carbonyl compound, Rh2(CO)3L3 (Complex 8, IR v(CO) 1732, 1768, and 1957 cm"1) (12). The similar reaction of RhHL3 containing bulkier phosphines produced Rh2(CO)4L2 (L = P(cyclo-CeHii)3, PPh(f-Bu)2, P(f-Bu)3). These dinuclear carbonyl compounds can be prepared by treating trans-RhH(CO)L2 with CO at room temperature. The formation of Rh2(CO)3L3 requires several steps, and a plausible sequence is proposed below. 

Diphosphaferrocene, with chromium carbonyls, 5, 220 l,l -Diphospha[2]ferrocenophane, synthesis, 6, 210 Diphosphazanes, in dinuclear Ru complexes, 6, 674 l,l -Diphosphetanylferrocenes, preparation, 6, 200-201 Diphosphine borane complex, polypyrrole support for,... 

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