(TELLUROLATO)CHROMIUM COMPLEXES - SYNTHESES AND CRYSTAL-STRUCTURES OFCPCR(CO)3(TEPH), [CPCR(CO)2(TEPH)]2, AND [CPCR(TEPH)]2TE

The predominant product isolated from the reaction of [CpCr(CO)3]2 (1; CP = eta5-C5H5) with 1 molar equiv of Ph2Te2 Varies with reaction con ditions as follows: CpCr(CO)3(TePh) (2; 67% yield, from an instantaneo us reaction at ambient temperature), [CpCr(CO)2(TePh)]2 (3; 80% yield, after 4.5 h at 60-degrees-C), and [CpCr(TePh)]2Te (4; 70% yield, afte r 4 h at 80-degrees-C). Thermolysis studies showed an interconversion between 2 and 3, accompanied by slow total decarbonylation to 4. An NM R-tube reaction of [CpCr(CO)2]2 with Ph2Te2 at 70-degrees-C for 2 h re sulted in the formation of 2 (58%), 3 (4%), and 4 (34%). The complexes , 2-4 have been elementally, spectrally, and structurally characterize d. Crystal data: 2, monoclinic, space group P2(1)/c, a = 10.8250(8) an gstrom, b = 8.6891(6) angstrom, c = 15.5263(7) angstrom, beta = 98.880 (5)-degrees, V = 1442.9(2) angstrom3, Z = 4; 3, triclinic, space group P1BAR, a = 10.0493(8) angstrom, b = 11.0612(6) angstrom, c = 13.263(1 ) angstrom, alpha = 102.021(6)-degrees, beta = 93.791(7)-degrees, gamm a = 105.652(5)-degrees, V = 1376.7(2) angstrom3, Z = 2; 4, monoclinic, space group P2(1)/n, a = 10.1595(7) angstrom, b = 21.505(1) angstrom, c = 10.615(1) angstrom, beta = 95.607(8)-degrees, V = 2308.1(5) angst rom3, Z = 4.