Indium complexes pyridines

AI(TPP)(Et), where six-coordinate adducts were obtained upon addition of imidazole For the indium complexes, irradiation in benzene and pyridine leads to a reduced complex whose ESR trace suggests - at least partly - a metal centered reduction leading to radical species stabilized by pyridine. These radicals then add carbon dioxide to give the insertion products. 

The five-co-ordinate indium complexes CaFsInChLCL = MesN CHa-CHa NMes, 2,2 -bipyridyl, 1,10-phenanthroline, 2,2 6, 2"-terpyridyl, or PhaP-CHa CHa -PPha) are obtained by reaction of the dioxan complex CeFsInCIaCCaHsOa) (Vol. 2, p. 430) with the appropriate ligands. Reaction of the dioxan complex with pyridine, triphenylphosphine, or dimethyl sulphoxide yields indium(iii) chloride and a tris-pentafiuorophenylindium complex, and the compounds (CeFs)iiIn(quinolin-8-olate)3- ( = 1 or 2) have also been prepared. ... 

The CO2 activation reactions seen for aluminum porphyrins are also observed for In(Por)Me (Por = OEP, TPP), which will insert CO2 in the presence of pyridine and under irradiation by visible light to give the acetato complex In(Por)OC(0)Me. The indium acetato product has been characterized by X-ray crystallography, whereas in the aluminum complex it was observed only by spectroscopy. An alternative synthesis of the acetato complex is by treatment of ln(Por)Cl by alumina and water, followed by acetic acid. For the indium and... 

Cationic indium(III) complexes could not be prepared with pyridine, but species such as [In(bipy)3]3+ and [In(phen)3]3+ are known as the perchlorate62 or nitrate64 salts, and [In(terpy)2](C104)3 has also been reported.67 Stability constants have been measured in the In3+/bipy and In3+/phen systems71,72 and for some substituted pyridines.9 The adducts of indium(III) halides and pseudohalides with pyridine and substituted pyridines have been... 

Sodium tetraazidoahiminate complexed by pyridine and tetrahydrofuran and analog-uous indium and gallium derived materials were obtained, the last uncomplexed. They are explosive on rapid heating, sodium tetraazidogallate at 150 C, and shock... 

Addition of pyridine or y-picoline (L) to the complex produces In(TBC)XL [3,5-di-/-butylcatecholate indium Ill) halide adducts]. The product recrystallized from DMF having the composition [In(TBC)I(pic)2] 2DMF belongs to the monoclinic... 

The chemical properties of indium are typical of those of Group 13 of the Periodic Table. Most of indium s oxides, salts, and compounds involve the +3 oxidation state (e.g., In203, In[N03]3> and InCl3) many of these compounds are electron-pair acceptors, forming addition compounds with donor molecules (e.g., InBr3 py, py = pyridine). Neutral, cationic, and anionic complexes are also known. Several interesting compounds are derived from the +1 and +2 oxidation states of the element. 

Both irradiation by visible light and pyridine are required for the above insertion. The same carboxylate complexes can be prepared by reaction of acetic acid with either the alkyl(aryl)indium(III) porphyrins or the aquohydroxoindium(III) porphyrins. 

The presence of pyridine and irradiation by visible light are required for the insertion of carbon dioxide into the indium-carbon o bond. However, the UV-visible spectrum of the starting complex is invariant with increasing amounts of pyridine, thus implying a five coordinate species in the media studied. These results contrast with those obtained for... 

Addition of six allylindium reagents to 2- and 3-pyridinecarboxaldehyde, and to glyoxylic acid (OHCCO2H), has been studied in water. " The stereoselectivity crosses over between the pyridine aldehyde isomers, which provides evidence for intramolecular complexation of indium by the pyridine nitrogen in the 2-position. The chelation ability of the 2-aldehyde is also compared to that of glyoxalic acid. 

---