I , Cu CO

CARBONYL[TRIS(3,5-DIMETHYLPYRAZOLATO)HYDROBORATO] -COPPER(I), Cu(CO)[(Me2pz)3BH] 

The residue is extracted twice with freshly distilled CO-saturated ether (100 mL), while the reaction vessel is kept under a CO atmosphere. Filtration of the extract and collection of the filtrate is performed using a conventional Schlenk-type apparatus, which is firstly evacuated (water pump) and then kept under a CO atmosphere. Slow filtration of the extract leaves a white residue and gives a clear colorless filtrate. The volume of the filtrate is reduced to ca. 20 mL by 

Thermal decomposition results in loss of the carbonyl ligand, followed by disproportionation to give blue Cu [(pz)3BH] 2 and copper metal. The carbonyl group is also displaced by a variety of ligands, L, to give the complexes Cu(L)[(pz)3BH], most of which are stable in air. Examples with L = PR3, P(OR)3, AsR3, SbR3, and CNR have been described.2 

The nomenclature used to represent the clathrochelate is from Reference 1. The chemicals employed in the synthesis are commercially available (reagent grade wherever possible) and are used without further purification. Elemental analyses were performed by Chemalytics, Inc., Tempe, AZ. 

The product has appreciable solubility in dichloromethane and more limited solubility in both benzene and pyridine. The Mossbauer spectrum and electronic spectrum of this clathrochelate are similar to those of other iron tri(glyoxime) cages.2 The compounds show an intense absorption band at 22,200 cm 1(e = 17,900). Several dominant bands in the infrared spectrum along with their proposed assignments are 1589 cm 1 (C=N stretch) 1495 cm 1 (C—Cand C=N stretch) 1234 and 1064 cm 1 (N—O stretch), and 1209 cm 1 (B—O stretch).3 In dichloromethane-d2, the pmr spectrum consists of two unresolved triplets (relative area = 24) at 1.78 and 2.91 ppm downfield from internal TMS and two multiplets (relative area 10.3) at 7.3 and 7.7 ppm downfield.3 The two multiplets are strikingly similar to that observed in the spectrum of phenyl- 

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Diorganotin(IV) complexes with 4//-pyrido[l,2-n]pyrimidin-4-ones 109 (96MI4), complexes of 2-methyl- and 2-methyl-8-nitro-9-hydroxy-4//-pyrido[l,2-n]pyrimidin-4-ones with Ag(I), Cu(II), Ni(II), Co(II), and Mn(II) ions (00MI23), 2,4-dimethyl-9-hydroxypyrido[l, 2-n]pyrimidinium perchlorate and its complexes with prasedynium, neodymium, samarium and europium (00MI24) were characterized by UV spectroscopy. 

It is believed [1135,1136] that the decomposition of metal complexes of salicyaldoxime and related ligands is not initiated by scission of the coordination bond M—L, but by cleavage of another bond (L—L) in the chelate ring which has been weakened on M—L bond formation. Decomposition temperatures and values of E, measured by several non-isothermal methods were obtained for the compounds M(L—L)2 where M = Cu(II), Ni(II) or Co(II) and (L—L) = salicylaldoxime. There was parallel behaviour between the thermal stability of the solid and of the complex in solution, i.e. Co < Ni < Cu. A similar parallel did not occur when (L—L) = 2-indolecarboxylic acid, and reasons for the difference are discussed... 

The direct reduction of Cu(Il) acetate to Cu(I) by CO at high pressures (up to 1360 atm) in aqueous solution at 120 °C shows several kinetic paths, the rate... 

Scheme 10. Noyori synthesis of 6,7-dehydro-3-hydroxytropanes 168 and 169. Reagents i, Fe2(CO)9, C6H6, 50°C ii, 2n-Cu, NH4C1,20°C iii, DIBAH, THF, -78- 20°C.

Macrocyclic ligands have also been effective in stabilizing less-common, lower oxidation states for a variety of metal ions. In particular, a considerable number of investigations have been concerned with the formation of stable Ni(i), Cu(i), Fe(i) and Co(i) species. 

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