15in which the metal-metal separation more closely approaches that of the bis-(dipyrromethene) macrocycles at 5.145 (1) A, the copper(I1) ions are reduced to copper(1) via one dielectronic step.The variability of the nature of the two one-electron reductions of the dicopper(I1) sites suggests the utility of these complexes as catalysts for the activation of small molecules via concurrent two-electron reductions. Of considerable interest, in view of the simultaneous one-electron reduction steps in the CI-, N3-, and NCSsalts, is the potential of these complexes to catalyze the oxidation of organic substrates. Preliminary results in this direction indicate that the azido complex catalyzes the oxidation of 3,5di-tert-butylcatechol in the presence of molecular oxygen. These studies will be reported in detail elsewhere. (28) Agnus, Y . ; Remy, L.; Gisselbrecht, J.-P.; Weiss, R. J. Am. Chem. SOC. 1984, 106, 93-102.Acknowledgment. Support of this research by the University of Kansas Biomedical Sciences Support Grant 4306-071 1-9 is gratefully acknowledged. K.B.M. thanks Prof. Reynold T. Iwamoto for helpful discussions.Registry No. 1 ( n = 3), 98737-20-3; 3,3'-diethyl-5,5'-diformyl-4,4'dimethyldipyrromethane, 967-68-0; 1,3-propanediamine, 109-76-2; Pb2-(bi-dptmd)(SCN),, 98759-99-0; Zn,(bi-dptmd)(CI),, 98760-00-0; Cu2-(bi-dptmd)(CI),, 98760-01-1; Cu2(bi-dptmd)(CIO4),, 98760-02-2; Cu,-(bi-dptmd)(BF,),, 9308 1-48-2; C~2(bi-dptmd)(N~)~.'/~CH,OH, 98760-04-4; Cu2(bi-dptmd)(SCN),, 98760-05-5; Zn2(bi-dpen)(C1),, 98760-06-6; C~~(bi-dpen)(ClO,)~, 98777-04-9; C~~(bi-dptmd)(N,)~, 98760-03-3; ethylenediamine, 107-1 5-3.

No abstract

Polynuclear chromium carbonyl complexes of the general formula [Cr4(CO)12^3-OR)4]4-(R = H, C6H5) have been prepared as their Et4N+ salts. Reaction of Cr(CO)6 with excess hydroxide ion in aqueous THE solution yields [Cr4(CO)12(^3-OH)4]4". The X-ray structure of [Et4N]4[Cr4(CO)12(g3-OH)4] has been determined. The structural features of the tetraanion consist of a cubane-like A4B4 (A = chromium, B = oxygen) arrangement with triply bridging M3-hydroxide groups and Cr(CO)3 units. The Cr-Cr distance within the Cr404 core is nonbondiitg (3.33 (5) Á (average)), consistent with a closed-shell metal configuration.The crystals are monoclinic (space group 12/a) with cell constants a = 21.827 (7) Á, b = 12.236 (2) A, c = 22.899 (4) A, ß = 116.49 (2)°, V = 5474 (5) A* 3, and Z = 8. The µ3-1 derivative, [Et4N]4[Cr4(CO)12^3-OC6H5)4], has been prepared by treatment of Cr(CO)3(CH3CN)3 with [Et4N] [OC6H5] in equimolar concentrations and characterized by spectroscopic methods. Polynuclear Chromium Carbonyl Tetraanions Table II. Selected Bond Distances (Á) and Angles (deg) for [Cr4(CO)12(M3-OH)4]4-Cr-0", Cr(l)-0(7) 2.126 (4) Cr(2)-0(7) 2.145 (3) Cr(l)-0(8) 2.122 (4) Cr(2)-Q(7) 2.107 (3) Cr(l)-0(8) 2.111 (3) Cr(2)-0(8) 2.112 (4) Cr--C Cr(l)-C(l) 1.787 ib) Cr(2)-C(4) 1.770 (b) Cr(l)-C(2) 1.787 (7) Cr(2)-C(5) 1.791 (b) Cr(l)-C(3) 1.803 (8) Cr(2)-C(6) 1.798 (7) C-O C(l)-0(1) 1.189 (7) C(4)-0(4) 1.201 (b) C(2)-0(2) 1.174 (7) C(5)-0(5) 1.178 (7) C(3)-0(3) 1.168 (8) C(b)-0(6) 1.174 (7)Cr-OwrCr Cr(l)-0(7)-Cr(2) 100.5 (2) Cr(l)-Q(8)-Cr(l) 106.1 (2) Cr(l)-G(7)-Cr(2) 102.7 (2) Cr(l)-G(8)-Cr(2) 102.7 (2) Cr(2)-0(7)-Cr(2) 106.5 (1) Cr(l)-Q(8)-Cr(2) 102.1 (2)0"3-Cr-0M3 0(7)-Cr(l)-0(8) 74.8 (1) 0(7)-Cr(2)-Q( 7) 72.7 (1) 0(7)-Cr(l)-0(8) 76.1 (1) 0(7)-Cr(2)-0(8) 75.7 (1) 0(8)-Cr(l)-0(8) 72.9 (2) 0(7)-Cr(2)-0(8) 75.4 (1)Cr-C-O Cr(l)-C(l)-0(1) 174.0 (5) Cr(2)-C(4)-Q(4) 174.6 ( 6)Cr(l)-C(2)-0(2)174.3 (6) Cr(2)-C(5)-0(5) 173.5 (6) Cr(l)-C(3)-0(3) 173.7 (6) Cr(2)-C( 6)-Q( 6) 169.4 (6)

The reactions of the dinuclear phosphorus ylide gold(I) complexes (II) with the alkyl halides RZX, yielding the Au(II) alkyl halide adducts (I), are studied.

The X-ray structure of Cs(2)[Ni(CN)(4)].H(2)O and the polarized single-crystal UV absorbance spectra of Cs(2)[Ni(CN)(4)].H(2)O and Cs(2)[Pt(CN)(4)].H(2)O are presented. The two complexes are isostructural, with helical arrangements of M(CN)(4)(2)(-) ions in which there is moderate metal-metal electronic perturbation resulting in a spectral red shift from solution in the UV absorbance spectra. In addition, we have modeled the nickel system with a ZINDO calculation of a three-molecule segment of the helix and have found remarkably good agreement with experiment, including excellent reproduction of the red shift. Crystal data are as follows: Cs(2)[Ni(CN)(4)].H(2)O, hexagonal, space group P6(1), a = 9.5260(10) A, c = 19.043(2) A, V = 1496.5(3) A(3), T = 100 K, Z = 6, 4335 observed data, R = 0.016, R(w) = 0.034.