Dpb ligand

Similarly, Peters studied the coordination of the DPB ligand 80 to CuCl.15 Along with the desired anionic complex 81, a small amount (< 15%) of the neutral DPB Cu(I) complex 82 was obtained, as the result of the cleavage of a boron-aryl bond (Scheme 47). In order to get complete spectroscopic data, an... 

At this stage, the formation of M-B interactions upon coordination of MPB 7b and 7c to Au and DPB 8a to Rh, Pt, and Pd did not allow direct comparison to estimate the influence of the second phosphine buttress. We thus investigated the coordination of DPB ligands to AuCl. Complex 115a was obtained in high yield from the reaction of 8a with [AuCl(SMe2)] in dichloromethane at room temperature (Scheme 66). 25... 

The kinetics of the reaction are first-order in complex and zero-order in phosphine, and dechelation of cod is proposed as the rate-determining step. Triphenyl phosphite displaces one molecule of l,4-bis(diphenylphosphino)butene (dpb) from [Ni(CO> (dpb) J (in which one dpb ligand is unidentate). Significant enhancement of the substitution rate is observed on addition of CF3CO2H and, to a lesser extent, H2SO4, which may indicate that protonation of the complex facilitates the reaction. 

In the mid 2000s, we initiated a comprehensive study of the coordination properties of orf/zo-phenylene bridged PBs. The DPB 8a was found to react with half an equivalent of [Rh2(g-Cl)2(nbd)2] in dichloromethane at room temperature (Scheme 62) 23 The yellow complex 108 that formed spontaneously was collected (92% yield) and analyzed spectroscopically. The 1H, 13C, and 31P NMR data substantiated the displacement of the labile nbd ligands at rhodium by the phosphine moieties. In addition, the mass spectrum indicated a dimeric structure of general formula [Rh2( i-C1)2(DPB2] and the nB NMR resonance signal observed at... 

In order to prepare a dirhodium compound, Rh2(DPB), the cofacial bispor-phyrin, H4(DPB), which was introduced in Sect. 3.2.1, was metallated to yield dirhodium(III) compounds with iodide and/or ethoxycarbonyl as axial ligands [279], While iodide is supposed to be able to reside inside the diporphyrin cavity, the ester moiety is located outside the cavity, since the compound (RhCOOEt)2(DPB) does not add triethylphosphane, contrary to the diodide. Photolysis of all Rh(III) derivatives obtained yielded the wanted product,... 

Os(II) complexes having phosphonic acid derivatized bipyridyl ligands (Scheme 1) have also been studied. The phosphonic acid complexes exhibit stronger adsorption to the semiconductor surface, which offers some advantages in devices. The complexes [Os(dpb)3]2+, [(dpb)20s(Cl)2], and [(dpb)20s(CN)2] have been investigated by Zabri et al. [122]. The photophysical properties of the complexes are reported and a comparison of the performance of DSSCs is made relative to [(dcb)2Ru(SCN)2]. Remarkably, absorption into the spin forbidden Os to dpb MLCT absorption resulted in high efficiencies in the 600-700-nm spectral region. 

Ligand abbreviations are as follows pop, dianion of pyrophosphite (p20sH2 " ) pep, dianion of /x-methylenebis(phosphite) im, anion of imidazole 4-mpyt, anion of 4-methylpyridine-2-thiol pyt, anion of pyridine-2-thiol pymS, anion of pyrimidine-2-thione bttz, anion of l,3-benzothiazole 2-thiol form, anion of di-p-tolylformaraidine dpb, /V,A -diphenylbenzamidine mhp, anion of 6-methyl-2-hydrox3T)yridine chp, 6-chloro-2-hydrox3T)yridine dpt, 1,3-diphenyltriazen. 

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