Reaction of 2-((.alpha.-R-benzylidene)amino)pyridines [R = CH3, 4-(CH3O)C6H4] with RhCl(L)3 or Rh2Cl2(CO)4: formation and structure of a rhodium(II) dimer

The reaction of 2-(({alpha}-methylbenzylidene)amino)pyridine (L{sub 1}) with RhCl(PPh{sub 3}){sub 3} resulted in the formation of cis-(Cl(PPh{sub 3}){sub 2}(L{sub 1})Rh{sup I}){center dot}S (1, S = solvent). The reaction of 2-(({alpha}-(4-methoxyphenyl)benzylidene)amino)pyridine (L{sub 2}) with Rh{sub 2}Cl{sub 2}(CO){sub 4} (4) under identical conditions resulted in the formation of cis-(Cl(CO){sub 2}(L{sub 2})Rh{sup I}) (2). The ligand L{sub 1} when treated with the same Rh complex 4 at 90{degree}C in an autoclave for 18 h resulted in the formation of (Cl(CO)(L{sub 1}-H)Rh{sup II}){sub 2} (3). Compound 1 crystallized in the triclinic space group P{bar 1} with Z = 2 and lattice parameters a = 10.9817 (8), b = 12.2447 (12), c = 17.800 (3) {angstrom}, {alpha} = 94.221 (10), {beta} = 101.770 (9), {gamma} = 92.022 (7){degree}, V = 2333.8 (4) {angstrom}{sup 3}. Compound 2 crystallized in the monoclinic space group P2{sub 1}/c with Z = 4 and lattice parameters a = 10.845 (6), b = 11.161 (6), c = 17.161 (9) {angstrom}, {beta} = 86.61 (1){degree}, V = 2073.58 {angstrom}{sup 3}. Compound 3 crystallized in the monoclinic space group P2{sub 1}/c with Z = 4 and lattice parameters a = 8.0708 (16), b = 20.907 (6), c = 16.373 (2) {angstrom}, {beta} = 90.078more » (14){degree}, V = 2762.6 (1.0) {angstrom}{sup 3}. The structures of the complexes reported are compared and contrasted with analogous complexes of rhodium.« less