O- and S-donor ligands

O- and S-donor ligands. [Tl2Cu(C03)2] has been reported. Isothermal evaporation of a solution of CuSO and CsSO at 80°C gives [Cs3Cu2(OH)2-(S04)3],2H20. The reaction of HCIO with Cu(OAc)2 in acetic acid shows the equilibria 

CUjtOAc) + 2HCIO4 2Cu(OAc)C104 + 2HOAc Cu2(OAc)4 + 4HCIO4 2Cu(C104)2 -I- 4HOAc 

Bregeault, and G. Pannetier, Bull. Soc. chim. France, 1971, 3935. 

Sawada, H. Ohtaki, and M. Tanaka, J. Inorg. Nuclear Chem., 1971, 34, 625. 

The complex [Cu(SCN)3] has been observed in studies on the CuO-NH4CNS-NH4NO 3-H2O system. 3- Diphenylphosphinothioyl-1 -phenyl- 

O- and S-Donor Ligands. In frozen aqueous glass, [Ti(H20)6] has an axial spin Hamiltonian with = 1.988 + 0.002, and g = 1.892 0.002. The stability constant of TiCP in aqueous HCl for p = 0 is loge Kq = 1.27—1.28 in good agreement with values obtained for CrCP and FeCP The stability constant of TiSO has also been determined.  

Photoreduction of oxalato-Ti complexes in aqueous oxalic acid gave oxalato-Ti complexes which catalysed the photosensitized decomposition of oxalic acid to CO2 and CO. Hydrolysis also occurred in the initial stages of irradiation e.p.r. signals characteristic of oxalate radicals were observed. Photochemical reduction of Ti compounds in alcohol solution is characterized by phototransfer of an electron followed by removal of H from the alcohol to give RCHOH (R = H or Me) and rearrangement of the first co-ordination sphere to give different Ti complexes depending on the temperature.  

The thermal decomposition of 1,4-dioxan and pyridine complexes of TiCls has been investigated. Dichlorotetrakis(propan-2-ol)titanium(m) chloride has an ionic structure four propan-2-ol molecules and two cis chlorines make up the distorted-octahedral co-ordination sphere of the Ti in the cation. 

The stability order for Ti complexes with a-hydroxy-acids of glycolate lactate mandelate is not the order of base strength of the ligands.  

Triethyl or tri-n-butyl thiophosphates react with TiCl3 at high temperatures to give polynuclear dialkoxythiophosphate complexes (TiL3) polymerization occurs via —S—P(0R)2—O— bridging.  

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The Zn + ion interacts favorably with N-, O- and S-donor ligands and shows a strong preference for tetrahedral over octahedral coordination in enzymes. In the case of model complexes, Zn + can form four-, five- and six-coordinate complexes, dictated by the... 

The chloro complex CrCl(TPP) is a non-electrolyte in DMSO and neutral N, O and S donor ligands will bind to give six-coordinate species.1255 There is little difference in the stability... 

Bis(cyclopentadienyl) niobium complexes halides, 5, 90 N-donor ligands, 5, 94 O- and S-donor ligands, 5, 93 P-donor ligands, 5, 94... 

The number of nickel(U) complexes with mono-, bi- and poly-dentate ligands containing tertiary phosphines as a donor group is very large and increases day by day while complexes with tertiary arsines are less numerous and those with stibines are rarer still. The number of nickel(II) complexes with mixed donor ligands containing N, O and S donor atoms besides P or As is also very large. 

The coordination chemistry of silver has historically been centred on the reaction of silver(I) ions with N-donor ligands and halides. However, an extensive chemistry now exists for P- and S-donor ligands, whilst for O-donor ligands only weak complexes are generally formed and they have been studied in much less detail. Based on the reactivity and stability of its coordination complexes, the silver(I) ion has been characterized as a class B or soft acid, for which the following stability order is observed N P>As>Sb 0 S Se Te FComparative studies between ligands with these donor atoms allowed the relative stability of silver bonds to be determined as P > S > N > O. 

The solvent influences on the complex formation and stability have been reviewed by Golub et al.194 Several monomeric complexes of Hg(SCN)2 with N, O, P, As and S donor ligands are known with terminal Hg—SCN bonds.224-2 Some thiocyanate-bridged dimeric complexes of mercury(II) are also known.225,226 Recently the isolation of a mercury(II) thiocyanate complex with hexamethylenetetramine with exclusively N-bonded SCN groups has been published (Figure 9).233 The compounds (CH2)6N4-Hg(SCN)2 and (CH2)6N4-2Hg(SCN)2 exhibit covalently bonded Hg—s.394,595... 

The cycloaurated benzyl bipyridine complexes 112 114 undergo ligand replacement reactions of the chloride ligand with a wide range of C-, N-, O- and S-donor... 

Table 42 Some Mn" Compounds of Multidentate O—S Ligands in Which Both O and S Donors are Bound...

Hydridocarbonyls and carbonyl complexes containing C, N, O or S donor ligands are covered in later sections of this review. 

The electrophilic methylene ligand undergoes nucleophilic additions with PPhs, py, and CN-f-Bu. It reacts with O and S donors to give [ReCp2( -H2CE)]+ (E = O, S) and with N2CHTMS to form the olefin complex [ReCp2( ] -H2C=CHTMS)]+. 

Arsenic(III) has a considerable affinity for charged O- or S-donor ligands, the latter including dithioacid chelates, but complexes with neutral O, S, or Se donor ligands are much rarer. Here complexes of neutral ligands are discussed first and then complexes with charged anions. 

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