REACTIONS OF BIS(ACETONITRILE)TRIOSMIUM DECACARBONYL WITH SECONDARY MIXED AMINES NHRR' (R = CH2CH3, R' = CH3 OR NORMAL-CH2CH2CH3)

The reactions of the mixed secondary amines methylethylamine and n-propylethylamine with (CH3CN)2Os3(CO)10 (1) in benzene or dichloromethane at 25-45-degrees-C have been studied. In the case of methylethylamine five trinuclear products containing amine-derived ligands are obtained: (mu-H)(mu-eta-1-CHCHN(CH3)CH2CH3)Os3(CO)10 (4), (mu-H)(mu-eta-1-N(H)CH3)Os3(CO)10 (5), (mu-H)(mu-eta-2-CH3C = NCH3)Os3(CO)10 (6), (mu-H)(mu-eta-2-CH3CH2N(H)CH2)Os3(CO)10 (7), and (mu-H)(mu-eta-2-CH3N = CHCH2)Os3(CO)10 (8). With n-propylethylamine only two trinuclear products containing amine-derived ligands are isolated: (mu-H)(mu-eta-1-N(H)CH2CH2CH3)Os3(CO)10 (9) and (mu-H)(mu-eta-1-CHCHN(CH2CH3)CH2CH2CH3)Os3(CO)10 (10). Thermolysis of 7 at 68-degrees-C, containing the least activated amine ligand, in the presence of excess methylethylamine yields only 4 while in the absence of amine thermolysis at 98-degrees-C yields the dihydrido cluster (mu-H)2(mu-3-eta-2-CHCH = NCH3)Os3(CO)9 (11), which is also formed from 8 at similar temperatures. Compound 6 decarbonylates at 125-degrees-C to yield (mu-H)(mu-3-eta-2-CH3C = NCH3)Os3(CO)9. All compounds were characterized by H-1 NMR, infrared, and elemental analysis. For compounds 6, 7, and 10, solid-state structural investigations by X-ray diffraction techniques are reported. Compound 6 crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 9.605 (3) angstrom, b = 12.096 (3) angstrom, c = 16.572 (3) angstrom, and V = 1925 (1) angstrom 3 for Z = 4. Least-squares refinement of 2454 observed reflections gave R = 0.030 (R(w) = 0.034). Compound 7 crystallizes in the monoclinic space group P2(1)/c with a = 9.516 (2) angstrom, b = 12.975 (2) angstrom, c = 16.260 (3) angstrom, beta = 103.85 (2)-degrees, V = 1949 (1) angstrom 3 for Z = 4. Least-squares refinement of 2918 observed reflections gave a final agreement factor of R = 0.046 (R(w) = 0.045). Compound 10 crystallizes in the monoclinic space group P2(1)/c with a = 7.679 (2) angstrom, b = 19.250 (5) angstrom, c = 17.091 (5) angstrom, beta = 112.63 (3)-degrees, V = 2332 (2) angstrom 3, for Z = 4. Least-squares refinement of 3594 observed reflections gave R = 0.061 (R(w) = 0.061).