Group-13 diyl complexes

The group-13 diyl complexes are an example where quantum chemical studies determined the understanding of the metal-ligand bonding situation since the very first compound of the new class of molecules (CO)4Fe-AlCp was isolated and characterized by X-ray structure analysis [93]. The TM-ER bonding situation can be qualitatively... 

Fig. 1 Synthesis of homo- and heteronuclear group 13-diyl complexes with group 13 Lewis acidic orgcuiometallics...

Table 7.13 Calculated BDEs De (Do) (kcal/mol) of homoleptic iron and group-10 transition metal diyl complexes. ...

The preparation of helically well-ordered polymers with stable screw-sense, which is able to be transmitted to newly formed polymer main-chains effectively, is highly desired for the development of new methodology for the synthesis of optically active helical polymers. An aromatizing polymerization of 1,2-diisocyanobenzenes is promoted by methylpalladium(II) complexes, producing poly(quinoxaline-2,3-diyl)s.146-148 The polymerization proceeds with successive insertion of the two isocyano groups of the diisocyanobenzene to the carbon palladium bond of... 

Irradiation causes ring closure by valence isomerization of 1,3-diphosphacyclobutane-2,4-diyl 42 (R = 2,4,6-tri(tert-butyl)phenyl) to 2,4-diphosphabicyclo[1.1.0]butane 43 which on thermolysis yielded the gauche-1,4-diphosphabutadiene 44 <99AG(E)3028>. The same group of workers have isolated the carbene 45 (R as above) as the lithium salt of a trimethylalane complex 46 <99AG(E)3031>. 

TRANSITION METAL COMPLEXES WITH GROUP-13 DIYL LIGANDS ER (E = B, Al, Ga, In, Tl)... 

Metal salen complexes can adopt non-planar conformations as a result of the conformations of the ethane-1,2-diyl bridge. The conformations may have Cs or C2 symmetry, but the mixtures are racemic. Replacement of the ethylenediamine linker by chiral 1,2-diamines leads to chiral distortions and a C2 chiral symmetry of the complex due to the half-chair conformation of the 5-membered ring of the chelate. Depending on substitution at the axial positions of the salen complex, the symmetry may be reduced to Q, but as we have seen before in diphosphine complexes of rhodium (Chapter 4) and bisindenyl complexes of Group 4 metals (Chapter 10) substitution at either side leads to the same chiral complex. Figure 14.10 sketches the view from above the complex and a front view. 

The copper-catalysed, Ullman-type coupling of aryl, heteroaryl and alkenyl halides may be achieved at ambient temperature using copper(I) thiophene-2-carboxylate as catalyst.60 A new semiconducting poly(anthraquinone-l,5-diyl) with nitro groups at the 4- and 8-positions has been prepared by Ullman-type coupling using metallic copper or a zerovalent nickel complex as catalyst.61... 

Phosphine complexes such as IrCXt(PMe2Ph)2 are soluble in organic solvents 95 the hydrides,96 Ir(H)2Cl2(PR3)4, are photochemically reduced to Ir 1 species. Another unusual complex,97 [(Me3P)3Ir(biphBF)Cl]+, has a BF moiety inserted into the Ir—C bond of the biphenyl-2,2 -diyl group. 

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