Gold complexes phenanthroline

Abbate, F., Orioli, P., Bruni, B., Marcon, G. and Messori, L. (2000) Crystal structure and solution chemistry of the cytotoxic complex 1,2-dichloro(o-phenanthroline) gold(III) chloride. Inorganica Chimica Acta, 311, 1. 

Chan, C.-W., Wong, W.-T. and Che, C.-M. (1994) Gold(lll) photooxidants. Photophysical, photochemical properties, and crystal structure of a luminescent cyclometallated gold(lll) complex of 2,9-diphenyl- 1,10-phenanthroline. Inorganic Chemistry, 33, 1266-1272. 

The treatment of gold(III) complexes with the rigid bidentate ligand phen allows the synthesis of pseudo-pentacoordinate gold(III) derivatives. This is the case of [Au(dmp)(phen)PPh3](BF4)2 (288) (dmp = 2-(dimethylaminomethyl)phenyl)1699 or [AuCl(C4Ph4)(phen)].16 2 The donor atoms of the phenanthroline ligand occupy one equatorial and the axial position of a square pyramid with distances 2.154(8)A and 2.627(10)A in (288). 

Mononuclear complex formation was confirmed for the adduct of zinc(II) salt with 2-mercaptobenzothiazole and o-phenanthroline (253). The t/-S coordination is observed in the complexes of triphenylphos-phine gold with 2-mercapto-l-methylimidazole (254) (88JOM119), 8-mercaptotheophilline (255) (91IC3743), 2-mercaptobenzoxazole (256) [94AX(C)1420], and purine-6-thiol (257) (94AJC577). 

The formation of five-coordinate gold(III) has been demonstrated clearly in the complexes of 2,9-dimethyl-l,10-phenanthroline and 2,2 -biquinoline, which have the distorted square pyramidal structures (91) and (92). However, the structures of the ligands prevent square planar coordination, so that these examples are atypical.613-615 However, a related organometallic derivative, [AuCl(C4Ph4)(phen)], is known and has a similar distorted square pyramidal structure.616... 

One group of NADH oxidants, which does not fit the proposed reaction scheme in Fig. 2.4 are the metal complexes. Examples of this type include nickel hexacyanoferrate deposited on porous nickel electrodes [29], gold electrodes modified with cobalt hexacyanoferrate films [30] and adsorbed l,10-phenanthroline-5,6-dione complexes of ruthenium and osmium [31]. It is unclear how these systems work and no mechanism has been proposed to date. It may be worth noting that dihydronicotinamide groups have been shown to reduce aldehydes in a non-enzymatic reaction when the reaction is catalysed by zinc, a metal ion [15]. In a reaction between 1,10-phenanthroline-2-carboxaldehyde and N-propyl-l,4-dihydronicotinamide, no reaction was seen in the absence of zinc but when added to the system, the aldehyde was reduced and the nicotinamide was oxidised. This implies that either coordination to, or close proximity of, the metal ion activates... 

Co(phen) +/2+, Fe(phen)r/3+. Co(bpy) +/2+, Fe(bpy>r/3+ and Os(bpy)2+/3+ (where phen = 1,10-phenanthroline and bpy = 2,2 -bipyri-dyl). The binding was interpreted in terms of the interplay of electrostatic interactions of the metal coordination complexes with the charged sugar-phosphate backbone and the intercalative, hydrophobic, interactions within the DNA helix, i.e., the stacked base-pairs. Chronopotentiometric detection of the Co(bpy)3+ indicator was used [102] to monitor the hybridization onto a screen-printed carbon electrode of short DNA sequences from E. coli pathogen in environmental water samples. The couple Co(bpy) 5+/2+ was also used to evaluate the adsorption of DNA on gold electrodes [103-104]. 

Bisbipyridylsilver(H) perchlorate has been examined spectroscopically and a square planar structure was postulated (36) it is possible however that a structure of lower symmetry may be the correct one. It is apparently very difficult to prepare bisbipyridyl or phenanthroline complexes of gold(III). The compounds [AuLX2]X and [AuLX2]C104 have been prepared (X = Cl or Br). In nonaqueous solvents the compounds AuLXs have low conductivities this is attributed to the rapid establishment of the following equilibrium ... 

Mixing of equimolar solutions of [Cu(CH3CN)4]PF6 in acetonitrile and Zn porphyrin-containing macrocycle 44 [80] in dichloromethane, followed by addition of phenanthroline derivative 45 in dichloromethane afforded in quantitative yield precatenate 48" . Subsequently, this complex was combined with a stoichiometric amount of gold(III) 5,10-di(p-hydroxyphenyl)-15,20-di(3,5-di-fert-butylphenyl)porphyrinate [47] PF6 in DMF. The resulting so-... 

Yu H-X, Cui H, Guan J-B (2006) Cathodic electrochemiluminescence of acetonitrile, acetonitrile-1,10-phenanthroline and acetonitrile-acetonitrile-ternary Eu(III) complex systems at a gold electrode. Luminescence 21 81-89... 

Chahda, R.K., Kumar, R. and Tuck, D.G. (1987) The direct electrochemical synthesis of thiolato complexes of copper, silver, and gold molecular structure of [Cu(SC H4CH3-o) (l,10-phenanthroline)]2.CH3CN , Can. J. Chem., 65, 1336-1342. 

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