Silver carbonyl

Matrix isolation studies usually permit spectroscopic observation of the species M(CO), M(CO)2,. M(CO) , the coordinatively saturated molecule. In some early studies, species thought to be simple unsaturated carbonyls were in fact carbonyls of metal clusters Mx(CO) a very low concentration of metal in the matrix (e.g., I mol in 104 mol noble gas) has to be used to prevent clustering. All the partially coordinated carbonyls are only matrix species, that is, they only exist when completely isolated from other molecules of their own kind or from CO. The coordinately saturated carbonyls are of more interest in the context of this review. The following new molecules have been reported Au(CO)2 (84a) Ag(CO)3, Cu2(CO)6 (46, 87) Pd(CO)4 (22), Pt(CO)4 (69) Rh2(CO)g, Ir2(CO)g (37) M(CO)6[M = Pr, Nd, Gd, Ho, Yb (100), Ta (24), U (117)]. The Cu, Pd, Pt, Rh, and Ir carbonyls can be obtained by condensing the metal vapors with pure CO at 40 K and then pumping off excess CO to leave a film of the carbonyl. The Cu, Pd, and Pt carbonyls decompose under vacuum temperatures above -100°C, and the Rh and Ir carbonyls dimerize with loss of CO to give M4(CO)12 above -60°C. The gold and silver carbonyls are not stable outside matrix isolation conditions. Unfortunately, the literature is presently unclear about the stability of the Ta and lanthanide hexacarbonyls outside a matrix. 

Despite the fact that CO is reversibly bound to Ag(I), Strauss and co-workers1012 succeeded in isolating crystalline silver carbonyl complexes at low temperature under a CO atmosphere and studying the crystal structure of [Ag(CO)]+[B(OTeF5)4] and [Ag(CO)2]+[B(OTeF5)4r. 

J. S. Ogden, Infrared Spectroscopic Evidence for Copper and Silver Carbonyls, Chem. Comm. 1971, 978-979. 

D. McIntosh, and G. A. Ozin, Synthesis Using Metal Vapors. Silver Carbonyls. Matrix Infrared, Ultraviolet-Visible, and Electron Spin Resonance Spactra, Structures, and Bonding of Ag(CO)3, Ag(CO)2, AgCO, and Ag2(CO)6, J. Am. Chem. Soc. 98, 3167-3175 (1976). 

Silver carbonyl ferrocyanide, Ag3[Fe(CN)5CO], is obtained as a white curdy precipitate on addition of the potassium salt to silver nitrate solution in the presence of acetic acid.4 It rapidly darkens even when protected from the light. Insoluble in boiling acetic acid, it is slightly soluble in dilute mineral acids evolving hydrogen cyanide. Potassium hydroxide liberates silver oxide, potassium carbonyl ferrocyanide being simultaneously produced. 

Dioxepan-2-ones (103) have been manufactured from diols, paraformaldehyde, and carbon monoxide in the presence of a copper(I) or silver carbonyl catalyst (Scheme 10). Thus, treatment of CU2O with 98% H2SO4 and CO and reaction with paraformaldehyde and 1,2-propanediol under CO atmosphere gave 5-methyl-l,4-dioxepan-2-one in high yield <89JAP0i09358i>. By the same protocol, l,4-dioxepan-2-one could be obtained by cyclocondensation of trioxane with CO and... 

The Group 11 metals (Cu, Ag, Au) have been almost ignored copper(I) and gold(I) carbonyls are known only as guests in zeolite hosts [295, 296] and silver carbonyls are unknown. 

Carbonyls of almost all transition metals and even some of the main group metals are presently known (Tables 2.18-2.20). Carbonyls of the main group metals, some carbonyls of the transition metals possessing small numbers of d electrons, as well as platinum, palladium, copper, and silver carbonyls are unstable, and were obtained in carbon monoxide or argon matrices at low temperatures (4-10 K). 

Hurlburt, Anderson and Strauss have reported the preparation of the first isolable silver carbonyl (as opposed to matrix isolated species). Additionally, there has been developments in gold halo-carbonyl chemistry, with a number of new complexes reported... 

A) IR spectroscopy shows v(CO) at 2088cm The first Isolable silver carbonyl [Ag(CO)2][B(OTeFs)4] has been reported It is extremely hygroscopic and water vapour displaces the CO ligands. 

---