Variety of Donor Ligands

Molecules of CrCl3,2Me3N are five-co-ordinated with a basically trigonal-bipyramidal geometry. The average bond lengths are Cr—Cl = 223.8 (5) and Cr—N = 215 pm two Cl—Cr—Cl angles are 124.3 (I) and the other is 111.4 (2)°, The distortion from idealized symmetry may be attributed to electronic effects since in symmetry there will be one electron in an e MO.  

The heats and entropies of formation of the sulphato-complexes [Cr(en)3-(S0.3) ] (n = 1—3) have been reported and the complex with n = 1 has been shown to be the most stable. The reaction of cis- and tra 5-[Cr(en)2 Bt2] with DMSO affords mainly c/s-[Cr(en)2Br(DMSO)] and c/s-[Cr(en)2-(DMS0)2], which have been isolated, as have the thermodynamically less stable corresponding traus-complexes. The stoicheiometry and rate of aquation of rrn s-[Cr(en)2F2] have been determined and the sole pro- 

Hosegood and J. L. Burmeister, Synth. Inorg. Metal-org. Chem., 1971,1, 21. 

Triethanolamine complexes of chromium(iii) have been reported and characterized in i.r. spectra and thermal-decomposition studies. The chromium(iii) nitrilotriacetato-complex [CrL(H20)2] [L = N(CH2C02)3 ] complexes with thallium(iii) to give [ CrL3(0H)(H20) gTl] with a formation constant of 9 3 X 10 at 25 The hydrolysis and dimerization of [CrLlOHljV  

Mizuochi, A. Uehara, E. Kyuno, and R. Tsuchiya, Bull. Chem. Soc. Japan, 1971,44, 1555. 

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The osmium complexes undergo ready reaction with a variety of donor ligands for the ethylene adduct, the X-ray structure has been obtained and clearly indicates the folding back of the SR ligand and... 

The -organometallics show a reactivity pattern typical of an alkene bound weakly to a metal center. The moiety may be displaced easily by a variety of donor ligands such as CO or PR3 (R = OMe, Ph), and indeed many of the complexes are very air and water sensitive. Reactions can be monitored easily by the color change from the intense red or green of the adduct to the characteristic purple color of the free C60 molecule the other products tend to have much lower extinction coefficients [Eqs. (11) and (12)] (15, 26). 

The iron compound readily sublimes and yields well-formed, black lustrous crystals. The cobalt complex will also readily sublime, but dependent upon the temperature at which the crystals are formed, they can be either black or brown in color. The crystal structures of both the cobalt and iron complexes have been determined.3 The nickel complex sublimes only in small amounts with difficulty. All three complexes are unstable to air and water, and the nickel complex readily undergoes thermal decomposition above 100°C. All three compounds will also readily form complexes with a variety of donor ligands such as tertiary arsines or phosphines. The nickel compound usually forms 2 1 adducts such as [(C6HS )3P]2Ni(NO)I, while the iron and cobalt complexes often undergo disproportionation.5... 

Chromium (III) chloride forms adducts with a variety of donor ligands. The tetrahydrofuran complex CrCl3-3THF, which is obtained as violet crystals by action of a little zinc on CrCl3 in THF, is a particularly useful material for the preparation of other chromium compounds such as carbonyls or organo compounds, as it is soluble in organic solvents. 

The carbonyl chloride is an excellent source of other rhodium(I) species, and the halogen bridges are readily cleaved by a wide variety of donor ligands to give ds-dicarbonyl complexes ... 

A particular subset of these ligated dialkyls are those in which the ligand is tethered to the cyclopentadienyl ligand. Thus, chromacyclopentane and cycloheptane derivatives stabilized by the (7/ 7/ -Me4C5CH2CH2NMe2) ligand have been prepared and their reactivity supports the intermediacy of such metallacycles in the catalytic trimerization of ethylene. A variety of donor-ligand-substituted cyclopen-tadienylchromium(III) complexes with amino and phosphino substituents has been prepared and screened for an ethylene polymerization activity. ... 

Table 8 summarizes data reported for other chromium(iii) complexes containing a variety of donor ligands. 

The entry into this family of complexes is the dimer CORM-2, which reacts with a variety of donor ligands (L) cleaving the Ru-Cl-Ru bridge and forming mononuclear [Ru(CO)3Q2L] species (Equation 6.1)... 

A variety of donor ligand-free, dimeric zinc aryloxides of general formula [(X)Zn(/i2-OAr)2Zn(X)] (ArO = bulky aryloxide X = alkyl " or amide ) are known. 

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