Azobenzene cyclometalated complexes

Cyclohexyldienyl complexes, with Ti(IV), 4, 327 Cyclohexylisocyanides, with gold(I) halides, 2, 281 Cyclohexylphosphine, for semiconductor growth, 12, 9 Cyclohexyl selenides, preparation, 9, 480 Cyclohydrocarbonylation alkenes, 11, 515 alkynes, 11, 522 dienes, 11, 522 overview, 11, 511-555 for ring expansion, 11, 527 Cycloisomerizations, via silver catalysts, 9, 558 Cyclomanganation, product types, 5, 777-778 Cyclometallated azobenzenes, liquid crystals, 12, 251 Cyclometallated complexes for OLEDs... 

Five-membered cyclometallated complexes similar to (191) are produced from the reaction between alkenic imines and iridium complexes. The reaction of alkenic imines with [Ir(Cl)(C8H,4)2]2 in the presence of cyclohexylphosphine yields complex (193),442 which, when treated with Cl2, undergoes substitution without Ir—C bond rupture to give (194 reaction 114).441 Azobenzene or its derivatives react with [Ir(Cl)(C8Hl4)2]2 in the presence of PR3 (R=Ph, cyclohexyl) according to reaction (112) to yield the cyclometallated complex (195).441,442... 

Murahashi, S.-I. Tamba, Y. Yamamura, M. Yoshimura, N. Reactions of cyclometalated Pd complexes with organolithium compounds or Grignard reagents. Selective ortho alkylation and arylation of benzaldehydes, azobenzenes, and tertiary benzylic amines. J. Org. Chem. 1978, 43, 4099-4106. 

Cyclometalation is a common reaction of Pt complexes of suitable N- and P-donor hgands this gives organometallic derivatives with a Pt bond. For example, the product from azobenzene and [PtCLi] is the chloro-bridged dinuclear species (4). 

Several Pd(II) cyclometallated azobenzene complexes, having general structures (azb )PdBr(L) and (azb")PdBr(L) (12) where L = 4-stylbazole, have... 

On the other hand, a cyclometalated cobalt complex 7.52 is prepared by the reaction of the cyclopaUadated compound with NaCo(CO)4, as shown in Eq. (7.40), although cyclometalation of azobenzene with Co2(CO)g at a low temperature (80 °C) does not proceed [90]. Hence, the formation of isoindazolone 7.39 from azobenzene and CO in the presence of Co2(CO)g at 190 °C is presumed to proceed via the cyclocobalt complex 7.52. 

Numerous azobenzenes and imines have been used to prepare cyclopalladated ctmiplexes, and the liquid crystal properties of some of die products have been investigated. 1 Cyclometallated derivatives have also been prepared from 2-phenylpyiidines, > 2,6-diphenylpyridine, 6-phenyl bipy. O and 6-(2-thienyl) bipy.509 Other substrates subjected to cyclopalladation include amidines, thio- and selenoamides, ll> l N-phenylsulftmyl glycine, hydroxyquinoline derivatives, the drugs diazepam and prazepam, and PBu 3. Doubly cyclopalladated complexes have been prepared from 1,3-diacetylbenzene dioxime and also from N,N-dialkyl benzene-l,3-dicarbaldimines. The 2D NMR spectra of cyclopalladated 8-methylquinoline and benzo-(h)-quinoline show that a CH bond occupies a fifth coordination position above the square plane.520... 

A cyclometallated azobenzene eomplex 91 was identified as a new class of highly efficient photorefractive materials.Gyclopalladated azobenzenes with N,0 chelating ligands and cyclic voltammetric studies were reported.Mesomorphic materials exhibiting a nematic phase were derived from a cyclopalladated azo compound.Mesogenic cyclopentadienyl cyclopalladated azobenzene eomplexes were also made. " Reactions of cyclopalladated azobenzenes were studied with xanthates and dithiocarbamates yielding ternary complexes. " The products were studied electroehemically. 

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