THE 1ST TRIANGULAR TRINUCLEAR CLUSTER COMPOUNDS OF MOLYBDENUM WITH 9 CLUSTER ELECTRONS - [MO3(MU-3-O)(MU-CL)3(MU-O2CCH3)3CLN(PR3)3-N]1-N, N = 1-3

The first four M3X13 type molybdenum triangular trinuclear cluster compounds with nine cluster electrons are described in this paper: (Bu4N)2[Mo3OCl6(OAc)3].Me2CO (1), (Bu4N)[Mo3OCl5(OAc)3(PMe3)].2THF (2), [Mo3OCl4(OAc)3(PMe3)2] (3), and [Mo3OCl4(OAc)3(PMe3)2].THF (4). The first three compounds were obtained by chemical reduction of (Bu4N)[Mo3OCl6(OAc)3].Me2CO, and the last one was prepared as a byproduct from a reaction mixture containing MoCl3(THF)3, Na/Hg, S, NaOAc, and PMe3. In all four compounds, each metal atom has the formal oxidation state +3 and there are nine electrons for the metal cluster. Physical measurements indicated that these compounds are paramagnetic and have one unpaired electron, which is in good accord with theoretical calculations. In compound 1 the metal-metal bond distances are 2.617 (1), 2.598 (1), and 2.598 (1) angstrom. The crystals belong to the space group Cc with Z = 4. The unit cell dimensions are a = 22.600 (3) angstrom, b = 12.031 (2) angstrom, c = 23.110 (4) angstrom, beta = 113.51 (1)degrees, V = 5762 (2) angstrom 3. In compound 2, the metal-metal bond distances are 2.637 (1), 2.573 (1), and 2.567 (1) angstrom. It crystallized in the space group P2(1)/c with Z = 4 and the following unit cell dimensions a = 13.419 (3) angstrom, b = 19.882 (5) angstrom, c = 18.630 (5) angstrom, beta = 96.27 (2)degrees, V = 4940 (2) angstrom 3. Compound 3 belongs to the space group P2(1)/c with a = 10.381 (3) angstrom, b = 12.680 (2) angstrom, c = 19.402 (2) angstrom, beta = 90.09 (1)degrees, V = 2553.6 (8) angstrom 3, and Z = 4. The metal-metal bond distances are 2.5878 (5), 2.6117 (5), and 2.5764 (5) angstrom. Compound 4 forms triclinic crystals in the space group P1BAR with the following unit cell dimensions: a = 10.121 (2) angstrom, b = 11.013 (2) angstrom, c = 14.628 (3) angstrom, alpha = 97.71 (2)degrees, beta = 93.06 (2)degrees, gamma = 104.62 (2)degrees, V = 1556.9 (6) angstrom 3, and Z = 2. The metal-metal bond distances are 2.597 (1), 2.608 (1), and 2.5673 (9) angstrom.