Novel, very stable ruthenium and osmium containing terminal phosphinidene complexes [(eta(6)-Ar)(L)M=Mes*] (Ar=benzene, p-cymene; L=PR(3), CO, and RNC) have been prepared by dehydrohalogenation of novel [(eta(6)-Ar)MX(2)(PH(2)Mes*)] complexes in the presence of a stabilizing ligand. Xray crystal structures are reported for [(eta(6)-C(6)H(6))(PPh(3))Rud=PMes*] (9) and [(eta(6)-pCy)(PPh(3))Os=PMes*] (4). Dehydrohalogenation in the absence of a stabilizing ligand resulted in the new P-spiroannulated Ru(2)P(2)-ring structure 16. Dehydrohalogenation in the presence of but-2-yne gave a novel phosphaallyl complex [(eta(6)-Ar)Ru(eta(3)-R(2)PC(Me)CHMe)] 26, for which an X-ray crystal structure is reported. The mechanism by which 16 and 26 are obtained is presumed to involve the intermediate formation of the 16-electron (eta(6)-benzene)Rud=PMes* phosphinidene complex.

Stable, crystalline iridium-complexed phosphinidenes, Cp*(L)IrdPR, are readily synthesized by (a) the reaction of Cp*(L)IrCl 2 (2, L) PPh 3) with LiPHMes* and (b) dehydrohalogenation of Cp*(PH 2 R)IrCl 2 (5, R) Mes*, Is, Mes) with in situ capturing of transient Cp*Irt PR (4) with phosphines, phosphites, arsines, isocyanides, and carbon monoxide (L). Cp*Irt PR eluded direct detection. The X-ray crystal structures are reported for Cp*(PPh 3)IrdPMes* (3) and Cp*(CO)IrdPMes* (15). The more congested 3 has an E configuration for its IrdP bond, whereas 15 is obtained in its Z form. The 31 P NMR chemical shifts and 2 J PP coupling constants are diagnostic for the E and Z forms. More shielded phosphinidene resonances and larger coupling constants are typical for the E isomers. These iridium-complexed phosphinidenes react with gem-diiodides to form phosphaalkenes, but not with carbonyl groups.

A capillary electrophoresis detection technique for (small) peptides is presented, i.e. quenched phosphorescence, a method that is generally applicable and does not require chemical derivatization. For this purpose, a novel phosphorophore, 1-bromo-4-naphthalenesulfonic acid (BrNS), was synthesized. BrNS has sufficient water solubility and provides strong phosphorescence at room temperature over a wide pH range. The detection is based on the dynamic quenching of the BrNS phosphorescence background signal by electron transfer from the amino group of the peptides at pH 9.5-10. For the di- and tripeptides Val-Tyr-Val, Val-Gly-Gly, Ala-Ser, Gly-Asn, Gly-Ala, and Gly-Tyr, detection limits in the range of 5-20 microg/L were obtained. The novel technique is even a good alternative for the (limited) group of peptides containing tyrosine and, thus, exhibiting native fluorescence as well as strong UV absorption: using Gly-Tyr, Val-Tyr-Val, methionine enkephalin, and human angiotensin II as test compounds, quenched phosphorescence detection was found to compare favorably with absorption detection at 190- and 266-nm laser-induced fluorescence detection, as performed with a recently developed, small-size, quadrupled Nd:YAG laser.

The reaction of 10-phenyl-10-germa-9-silatriptycene (1b) with phenyllithium in THF/HMPA produced 9,10-diphenyl-10-germa-9-silatriptycene (1a), which had hitherto not been accessible. The reaction proceeds by attack of the phenyl anion on 1b via the intermediate silicate anion 7, which was identified by 29 Si NMR spectroscopy. The structure of 1a was confirmed by X-ray crystallography. As a model reaction, the attack of phenyllithium on triphenylsilane (8) and diphenylsilane ( 14) was investigated by 29 Si NMR spectroscopy, revealing the formation of a number of novel hydridosilicates analogous to 7.