名称:
NO bond cleavage and various bonding modes of the nitrato ligand in rhodium complexes: syntheses and structures of [Cp*Rh(η1-NO3)(μ-Cl)]2, {[Cp*RhCl(PPh3)(CNC6H11)]2(NO2)(NO3)}·2H2O, [Cp*Rh(η1-NO3)(η1,μ-N3)]2, [Cp*Rh(η2-NO3)(O3SCF3)], trans-{[Rh(PPh3)2(CN2,6-Me2C6H3)2](NO3)}·H2O, and {[Cp*2Rh2(η2,μ-NO2-N,O)2(η1,μ-N3)](PF6)}·0.5H2O
摘要:
The addition of 2 equiv. of AgNO3 to a dinuclear chloro-bridged Rh(III) compound, [Cp*RhCl2](2), resulted in the replacement of the terminal chloro ligand to give [Cp*Rh(eta(1)-NO3)(mu-Cl)](2) (1). On the other hand, the reaction of [Cp*RhCl2](2) with 4 equiv. of AgNO3 led to the formation of a mononuclear bis(nitrato)-rhodium compound, [Cp*Rh(eta(1)-NO3)(eta(2)-NO3)] (2). Compound 1 reacted With PPh3 and cyclohexyl isocyanide (CN-C6H11) to give a chiral compound, {[Cp*RhCl(PPh3)(CN-C6H11)](2)(NO2)(NO3)} 2H(2)O (3.2H(2)O), which shows an unusual example of the nitrate-to-nitrite reduction in the rhodium coordination sphere. The reaction of compound 2 with either NaN3 or N3SiMe3 gave a dinuclear (eta(1)-nitrato)-rhodium compound, [Cp*Rh(eta(1)-NO3)(eta(1),mu-N-3)](2) (4). On the other hand, on addition of silver triflate (AgOTf), compound 2 underwent replacement to give a monormclear (eta(2)-nitrato)-rhodium compound, [Cp*Rh(eta(2)-NO3)(OTf)] (5). In addition, compound 2 reacted with a mixture of PPh3 and 2,6-dimethylphenyl isocyanide (CN-2,6-Me2C6H3) to give trans-{[Rh(PPh3)(2)(CN-2,6-Me2C6H3)(2)](NO3)} . H2O (6. H2O), Which exhibits the complete elimination of all ligands in compound 2 and indicates the formal reduction of the rhodium metal from + 3 to + 1. The nitro-rhodium compound, {[Cp-2*Rh-2(eta(2), mu-NO2-N,O)(2)(eta(1),mu-N-3)](PF6)} . 0.5H(2)O (7 . 0.5H(2)O), was prepared by the reaction of [Cp*RhCl(dppf)](PF6) (dppf = Fe(eta(5) -C5H4PPh2)(2)) with a mixture of N3SiMe3 and AgNO3, Which also displays the N-O bond cleavage of nitrate (NO3-) to nitrite (NO2-). The structures of 1, 3 . 2H(2)O, 4, 5, 6 - HO, and 7 . 0.5H(2)O were determined by X-ray diffraction. (C) 2002 Elsevier Science B.V. All rights reserved.