Iodo-bridged complexes

The Pt + Pt intervalence transitions of such chain complexes occur in the regions 25,000-18,200 cm 1, 23,600-14,300 cm 1 and 20,600-7,500 cm 1 for chloro-, bromo-, and iodo-bridged complexes, respectively, the trend Cl > Br > I being the reverse of that of the conductivity of the complexes. The transition wavenumbers may be determined either by Kramers-Kronig analysis of specular reflectance measurements or from plots of the excitation profiles of Raman bands enhanced at or near resonance with the Pt I-PtIV intervalence band. The maxima have been found to be related to the Pt —PtIV chain distance, the smaller the latter the less being the intervalence transition energy (3). 

PhS, p-tolS) initially yields the bis(nitrile) complexes [MI2(CO) (NCMe)2(i72-RC2R )]. which dimerize to yield the iodo-bridged complexes [ M(/t-I)I(CO)(NCMe)(T)2-RC2R ) 2].245 The reactions of the diphenylacet-ylene molybdenum complex with donor ligands and alkynes are shown in Scheme 6. 

The iodo-bridged complexes 12 and 34 (formed by a simple halogen metathetic reaction of the corresponding chloro-bridged dimers with Nal in acetone, for example) both react with alkynes to afford heterocyclic products. 12 leads to a range of indoles 40 in a one-pot procedure, ... 

A versatile synthesis of monoamine platinum(II) complexes of the type ptCl3(amine)], where the nature of the amine ligand can be varied readily, involves treatment of the iodo-bridged dimer [PtI(/r-I)L]2 (L = NH3, methylamine, ethylamine, isopropylamine, cyclobutylamine, and... 

The reaction of [(DME)2Ybl]2(M-CioH8) with PhC=CH leads to the mixed iodo/ethynyl complex [lYb(p.-C=CPh) (DME)2]2 (Figure 93a). According to X-ray diffraction analysis, the molecule consists of two Ybl(DME)2 units bridged by two C=CPh groups. The central cychc fragment Yb-C Yb-C is planar. The homoleptic Yb(ll)... 

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