The complex [(triphos)(CO)2Re(OTf)] (1) reacts with disubstituted propargyl alcohols HC⋮CCR(R‘)OH in CH2Cl2 at room temperature (R = R‘ = Ph, Me; R = Ph, R‘ = Me), to give either allenylidene derivatives [(triphos)(CO)2Re{CCC(R)Ph}]OTf (R = Ph, 2; R = Me, 3) or the dinuclear vinylidene−carbene complex [{(triphos)(CO)2Re}2{μ-(C10H12)}](OTf)2 (5) (R = R‘ = Me) (triphos = MeC(CH2PPh2)3; OTf = CF3SO3 -). The secondary propargyl alcohol HC⋮CCH(Me)OH reacts with 1 in the presence of methanol to give the methoxyalkenyl Fischer-type carbene [(triphos)(CO)2Re{C(OMe)-CHCHMe}]OTf (11). Compound 11 has been authenticated by an X-ray diffraction analysis. The structure of this complex shows the metal center to be surrounded by a fac triphos ligand, by two mutually cis carbonyl groups, and by the organyl ligand in a slightly distorted octahedral geometry. The reaction with HC⋮CCH2OH results in the double addition of methanol to give the carbene complex [(triphos)(CO)2Re{C(OMe)(CH2CH2OMe)}]OTf (9). When the reaction between 1 and propargyl alcohol is carried out in the dichloromethane dinuclear vinylidene−carbene complex, [{(triphos)(CO)2Re}2{μ-(C6H6O)}](OTf)2 (10) is obtained.

Complexes [Pt(mu-N,S-8-TT)(PPh(3))(2)](2) (1), [Pt(mu-S,N-8-TT)(PTA)(2)](2) (2), [Pt(8-TTH)(terpy)]BF(4) (3), cis-[PtCl(8-MTT)(PPh(3))(2)] (4), cis-[Pt(8-MTT)(2)(PPh(3))(2)] (5), cis-[Pt(8-MTT)(8-TTH)(PPh(3))(2)] (6), cis-[PtCl(8-MTT)(PTA)(2)] (7), cis-[Pt(8-MTT)(2)(PTA)(2)] (8), and trans-[Pt(8-MTT)(2)(py)(2)] (9) (8-TTH(2) = 8-thiotheophylline; 8-MTTH = 8-(methylthio)theophylline; PTA = 1,3,5-triaza-7-phosphaadamantane) are presented and studied by IR and multinuclear ((1)H, (31)P[(1)H]) NMR spectroscopy. The solid-state structure of 4 and 9 has been authenticated by X-ray crystallography. Growth inhibition of the cancer cells T2 and SKOV3 induced by the above new thiopurine platinum complexes has been investigated. The activity shown by complexes 4 and 9 was comparable with cisplatin on T2. Remarkably, 4 and 9 displayed also a valuable activity on cisplatin-resistant SKOV3 cancer cells.

Reaction of the rhenium(I) allenylidene complex [Re{CCCPh2}(CO)2(triphos)]OTf (1; triphos = MeC(CH2PPh2)3, OTf = -OSO2CF3) with thiophenol, 2-thionaphthol, or allyl mercaptan gave selectively the α,β-unsaturated thiocarbene complexes [Re{C(SR)CHCPh2}(CO)2(triphos)]OTf (R = Ph (2), α-naphthyl (3), CH2CHCH2 (4)). A reversible reaction was observed for PhSH in DMSO at 80 °C. Compounds 2 and 3 have been found to react with sodium alkoxides, yielding the kinetic thioallenyl products [Re{C(SR)CCPh2}(CO)2(triphos)] (R = Ph (6a), α-naphthyl (7a)). These equilibrated in room-temperature solution with the thermodynamic thioalkynyl products [Re{C⋮CC(SR)Ph2}(CO)2(triphos)] (R = Ph (6b), α-naphthyl (7b)) to give stationary states (6a/6b, 40/60; 7a/7b, 20/80). Deprotonation of the thioallyl complex 4 gave the stable allenyl derivative [Re{C(SCH2CHCH2)CCPh2}(CO)2(triphos)] (8). Ammonia, aniline, and propargylamine each reacted with 1 to give the azoniabutadienyl compounds [Re{C(NHR)CHCPh2}(CO)2(triphos)]OTf (R = H (9), Ph (10), CH2C⋮CH (11)) via N−H bond addition across the CαCβ double bond. NMR spectroscopy showed the γ-alkynylammonium complex [Re{C⋮CCPh2(NH3)}(CO)2(triphos)]OTf (12) to be a transient intermediate along the reaction of 1 with ammonia. Treatment of 10 or 11 with sodium methoxide resulted in the selective deprotonation of the nitrogen atom to give the azabutadienyl compounds [Re{C(NR)CHCPh2}(CO)2(triphos)] (R = Ph (13), CH2C⋮CH (14)). The molecular structure of the azoniabutadienyl complex 11 was determined by a single-crystal X-ray analysis. The geometry around the rhenium center conforms to a slightly distorted octahedron, with the polyphosphine sitting on a face of the coordination polyhedron. In keeping with the azoniabutadienyl structure, the Re−Cα bond length is 2.151(7) Å, and the Cα−N distance is 1.300(9) Å.

Novel monoallenylidenes of Ru and Re and homobimetallic Ru/Ru and heterobimetallic Ru/Re complexes bridged by multiconjugated aromatic organic spacers such as bianthracenylidene and biphenylene were obtained and characterized by conventional spectroscopic techniques and elemental analysis. Electrochemical measurements coupled to spectroelectrochemistry and EPR spectroscopy proved that in the bis(allenylidene) complexes an electronic communication is present between either the two allenylidene bridges or the two metal centers, enticing extended intramolecular electronic mobility.

The platinum mixed-phosphine complexes (SP-4,2)-[PtCl(8-MTT)(PPh3)(PTA)] (2) and cis-[Pt(8-MTT)2(PPh3)(PTA)] (3) (MTTH2 = 8-(methylthio)theophylline, PTA = 1,3,5-triaza-7-phosphaadamantane) have been prepared from the precursor cis-[PtCl2(PPh3)(PTA)] (1), which has been fully characterized by X-ray diffraction determination. Antiproliferative activity tests indicated that the presence of one lipophilic PPh3 and one hydrophilic PTA makes 1-3 more active than the analogues bearing two PPh3 or two PTA. The reactivity of cis-[PtCl2(PPh3)2], cis-[PtCl2(PTA)2], and cis-[PtCl2(PPh3)(PTA)] with the bis(thiopurines) bis(S-8-thiotheophylline)methane (MBTTH2), 1,2-bis(S-8-thiotheophylline)ethane (EBTTH2), and 1,3-bis(S-8-thiotheophylline)propane (PBTTH2) has also been investigated. New binuclear complexes have been prepared and identified by spectroscopic techniques and their antiproliferative activities on T2 and SKOV3 cell lines evaluated.