A triosmium carbonyl cluster-boronic acid conjugate is used as a secondary carbohydrate probe in a SERS-based assay. The assay does not require conjugation of the metal carbonyl probe to a SERS-active species, and it utilizes the CO stretching vibrations of the metal carbonyl, which lies in a silent region of the SERS spectrum (1800-2200 cm(-1)), for quantification. High selectivity for glucose over fructose and galactose is obtained, and a human urine sample doped with glucose is detected accurately.

Conjugates of organometallic osmium carbonyl clusters and gold nanoparticles show a strong carbonyl signal in surface-enhanced Raman spectroscopy. The ease of bio-functionalization and the high stability and good dispersibility in aqueous solution make these conjugates excellent candidates for biomedical applications, as demonstrated by live-cell imaging with the carbonyl signals of OM-NP(PEG)-L conjugates.

Monostibine-protected ionic Au13 nanoclusters, namely, [Au13(L)8(Cl)4][Cl] (L = SbPh3, 2a·Cl; Sb(p-tolyl)3, 2b·Cl) were prepared by the direct reduction of Au(L)Cl with NaBH4 in dichloromethane.

Keywords: Drug design / Antitumor agents / Osmium / Ruthenium / Metallocenes / Ferrocifen Three osmium analogues 3a-3c of hydroxytamoxifen were prepared. The antiproliferative effects of these complexes were measured against two breast cancer cell lines (MCF-7 and MDA-MB-231) and compared with those of their homologues of ferrocene (1a-1c) and ruthenocene (2a-2c). The tamoxifen-like complexes 2c and 3c derived from osmium and ruthenium show good cytotoxicities against the two cell lines (IC 50 values between 2 and 3 μM), albeit lower than those of ferrocifen 1c (IC 50 between 0.5 and 0.8 μM). These complexes induce senescence of the cells at low concentration (0.5 μM). The mono-and diphenol complexes of osmium and ruthenium show little cytotoxicity against the two cell lines (2a, 2b, 3a, 3b; IC 50 ≈ 30 μM), whereas the iron analogues show

Two stable and water-soluble organometallic carbonyl cluster derivatives have been prepared and shown to enter the cell with ease. The CO stretching vibrations afford strong mid-infrared signals which have been demonstrated, for the first time, to be of utility in cell imaging via an IR microscope.

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The reaction of [(eta(6)-arene)RuCl(2)](2) (arene = C(6)Me(6), 1,4-MeC(6)H(4)CHMe(2)) with a large excess of the dianion of bis(2-mercaptoethyl) sulfide, (HSCH(2)CH(2))(2)S, obtained from deprotonation of the dithiol with freshly prepared NaOMe, gives the deep red, monomeric complexes [(eta(6)-arene)Ru(eta(3)-C(4)H(8)S(3))] (arene = C(6)Me(6) (5), 1,4-MeC(6)H(4)CHMe(2) (6)) in which the dianion is bound to the metal atom through one thioether and two thiolate sulfur atoms. Complex 5 reacts with [(eta(6)-C(6)Me(6))RuCl(2)](2) (4) in a 2:1 mole ratio to give a quantitative yield of the chloride salt of a binuclear cation [((eta(6)-C(6)Me(6))Ru)(2)Cl(mu(2)-eta(2):eta(3)-C(4)H(8)S(3))](+) (7) in which the thiolate sulfur atoms of the [(eta(6)-C(6)Me(6))Ru(eta(3)-C(4)H(8)S(3))] group bridge to a (eta(6)-C(6)Me(6))RuCl unit. This compound is also obtained directly from the reaction of 4 with the dithiolate, if the Ru dimer is used in large excess. The binuclear complex [((eta(6)-C(6)Me(6))Ru)(2)(MeCN)(mu(2)-eta(2):eta(3)-C(4)H(8)S(3))](PF(6))(2).MeCN, (9)(PF(6))(2).MeCN, is obtained by treatment of (7)Cl with NH(4)PF(6) in acetonitrile. Protonation of 5 with HCl gave the mono- and diprotonated derivatives viz. [(eta(6)-C(6)Me(6))Ru(eta(3)-C(4)H(9)S(3))]Cl, (8)Cl, and [(eta(6)-C(6)Me(6))Ru(eta(3)-C(4)H(10)S(3))]Cl(2), (10)Cl(2), respectively. The reaction of 5 with methyl iodide gives both the mono- and di-S-methylated derivatives. Treatment of 5 with dibromoalkanes, Br(CH(2))(n)Br (n = 1-5), effects ring closure to give the (eta(6)-C(6)Me(6))Ru dications containing the trithia mesocyclic zS3 (z = 8-12) ligands, isolated as their PF(6) salts. The X-ray crystal structures of 5, 6, the solvates of (7)Cl and (9)(PF(6))(2), and the trithia mesocyclic Ru complexes (eta(6)-C(6)Me(6))Ru(zS3)(PF(6))(2) (z = 8-11) are reported.

Thermolysis of Os 3 (CO) 11 (SbPh 3 ), 1, in refluxing octane gave initially the clusters Os 3 (µ-SbPh 2 )(µ-H)(µ 3 ,η 2 -C 6 H 4 )(CO) 9 , 2, and Os 6 (µ 3 -SbPh)(µ 3 ,η 2 -C 6 H 4 )(CO) 20 , 3. Prolonged heating gave the cluster Os 6 (µ 4 -Sb)(µ-H)(µ 3 ,η 4 -C 12 H 8 )(µ 3 ,η 2 -C 6 H 4 )(CO) 16 , 4, as the major product. In contrast, thermolysis in hexane at 115 °C in a Carius tube gave Os 6 (µ 4 -Sb)(µ-SbPh 2 )(µ-H) 2 -(µ 3 ,η 4 -C 12 H 8 )(µ 3 ,η 2 -C 6 H 4 )(CO) 15 , 5, Os 6 (µ 4 -Sb)(µ-SbPh 2 )(µ-H)(µ 3 ,η 2 -C 6 H 4 ) 2 (C 6 H 5 )(CO) 16 , 6, and Os 6 (µ 4 -Sb)(µ-SbPh 2 )(µ-H)(µ 3 ,η 6 -C 6 H 4 )(µ 3 ,η 2 -C 6 H 4 )(C 6 H 5 )(CO) 15 , 7, besides 2 and 3. It has been demonstrated that cluster 6 was formed from 2, while clusters 5 and 7 were formed from the further decomposition of 6. The reaction of 5 with SbPh 3 afforded a monosubstituted derivative, Os 6 (µ 4 -Sb)(µ-H) 2 (µ-SbPh 2 )(µ 3 ,η 2 -C 6 H 4 )(µ 3 ,η 4 -C 12 H 8 )(CO) 14 (SbPh 3 ), 8. The clusters 2-8 were all shown by single-crystal X-ray crystallographic studies to have a benzyne moiety acting as a four-electron donor to a triosmium fragment. In addition, 4 and 8 contain a novel µ 3 ,η 4 -biphenylene moiety bound to a triosmium framework, while 7 was found to have a µ 3 ,η 1 :η 1 :η 6 -C 6 H 4 ring.