Tetranuclear tetrahedral

For tetranuclear cluster complexes, three stmcture types are observed tetrahedral open tetrahedral (butterfly) or square planar, for typical total valence electron counts of 60, 62, and 64, respectively. The earliest tetracarbonyl cluster complexes known were Co4(CO)22, and the rhodium and iridium analogues. The... 

More recently, tetranuclear complexes, related to those previously obtained for both ruthenium and osmium, have been obtained for iron, and their structures have been established by X-ray analysis 118). The reported adducts are [Fe4(CO)11(RC2R1)2] (R = H, R1 = Me, Et, n-Pr R = R1 = Me), and are obtained in very low yield (<1%). For R = H, R1 = C2H5, the structure is shown in Fig. 16. This involves a distorted tetrahedral metal system with the two alkyne groups bonding in a manner similar to that observed for the "butterfly molecule [Co4(CO)10(EtC2Et)] 119). 

Derivatives of Diamantoidal Geometry. Figure 42 shows the tetrahedral (diamantoidal) geometry assumed by the four manganese atoms in complex [Mn406(tacn)4]4+ (tacn = 1,4,7-triazacyclononane), which was the first tetranuclear manganese complex to be structurally characterized.56,57... 

Polyauration starts from the carbon atom for which the species with four, five and six gold atoms have been prepared. These are available from the reaction of polyborylmethanes with [AuCl(PR3)] or trimethylsilyl diazomethanes with [0(AuPR3)3]+. The tetranuclear derivatives are formed with bulky phosphines and less sterically demanding phosphines enable the synthesis of the hypervalent species [230]. The structures of these complexes are tetrahedral, trigonal bypiramidal and octahedral, respectively (Figure 1.36). Many complexes of the type [RC(AuPR3)4]+ [231] have also been synthesized. 

Similar complexes have been prepared with nitrogen as a central hereroatom but to date only the tetranuclear and pentanuclear derivatives have been achieved from the reaction of ammonia with the oxonium complexes (Figure 1.37), with a tetrahedral or trigonal bipyramidal geometry, respectively [232]. Auration of polyamines or related... 

The tetrahedral CiuXt is the most common tetranuclear copper(I) species and primarily occurs (Figure 4.4, v) as the cubane structure Cu4X4L4, where X is Cl-, Br- pr I- and L is a... 

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