ISSN:
1572-901X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary β-Diketones react with [Mo(NO){HB(dmpz)3}I2] [HB (dmpz)3 = tris (3,5-dimethylpyrazolyl)borate] giving the cationic complexes [Mo(NO) {HB(dmpz)3}{OC(R)CR″C-(R′)O}]+ (R = R′ = Me, R″ = H, Me or n-Bu; R = R′ = Ph, R″ = H; R = Me, R′ = n-Bu, R″ = H), isolated as triiodide salts. Electrochemical studies show that these complexes exhibit three electrode processes: two associated with oxidation of I inf3 sup− and one with reduction of the metal-containing cation. Reduction of the cation where R = R′ = R″ = Me with cobaltocene afforded the neutral paramagnetic [Mo(NO) {HB(dmpz)3} {OC(Me)CMeC(Me′)O}], which was characterized by i.r. and e.p.r. spectroscopy. In contrast, 3-chloropentane-2, 4-dione reacts efficiently with [Mo(NO){HB(dmpz)3}I2] giving the known chloro-analogue, [Mo(NO)-{HB(dmpz)3}Cl2], and no β-diketonate complex was detected. The X-ray crystal structure determination of [Mo(NO){HB(dmpz)3} {OC(Me)CMeC(Me)O}]I3 confirms that the cation is six-coordinate and shows that the 559-01 (diketonate) bonds are slightly longer than in comparable compounds, implying that the β-diketonate ligand is not such a strong π-donor as alkoxide groups.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00136420
Permalink