POLYMETALLIC CHROMIUM ALKOXIDES - SYNTHESIS AND CRYSTAL-STRUCTURES OF (I-PRO)8CR2NA4(THF)4 AND (MU-3-OPH)10CR4(MU-3-O)3NA4(TMEDA)4

The reaction of (RO)8Cr2Na4(THF)4[R = i-Pr (1a), Ph (1b)] with TMEDA (TMEDA = N,N,N',N'-tetramethylethylenediamine) has been studied. While the isopropyl derivative 1a yielded the polymeric [(i-PrO)2Cr]n, in the case of 1b, the Cr(III) aggregate (PhO)10Cr4(mu-3-O)3Na4(TMEDA)4 (2) was formed via an unusual oxidation reaction. Crystal data for 1a and 2 are as follows: 1a is monoclinic, space group P2(1)/c with a = 11.979 (1) angstrom, b = 21.243 (1) angstrom, c = 12.009 (2) angstrom, beta = 113.75 (1)-degrees, V = 2796.9 (6) angstrom 3, Z = 2; 2 is triclinic, space group P1BAR, a = 14.332 (1) angstrom, b = 15.403 (1) angstrom, c = 26.447 (2) angstrom, alpha = 98.24 (1)-degrees, beta = 98.71 (1)-degree, gamma = 115.87 (1)-degrees, V = 5046.7 (8) angstrom 3, Z = 2.