Takashi Shibahara

Syntheses of sulphur-bridged molybdenum and tungsten coordination compounds

A. Introduction B. Syntheses of dinuclear molybdenum compounds (i) Mo,O,_,S, cores (n= l-4) (a) Synand anti-Mo,(O,),@S), cores (b) Synand anti-Mo,(O,)(S,)@-S), cores (c) Synand anti-Mo,(S,),@-S), cores (d) Syn-Moz(O,),(p-O)b-S) cores (ii) MO,@-S),, MO&-0)01-S), MO&S), Mo,(O,),@-S), and MO&)&-S) cores .... (iii) Mo(MoS,) and Mo(MoO,S) cores (iv) Mo,(&) cores (v) Miscellaneous C. Syntheses of trinuclear molybdenum compounds (i) Mo,(~~-S)@-S)~ cores (ii) Mo~(~~-S)@-O)~-&I-S). (n = O-3) and MO&,-O)(p-S), cores (iii) Triangular MO&-S)(p-S,), cores (iv) Non-triangular MO, cores D. Syntheses of tetranuclear molybdenum compounds (i) Cubane-type MO&-S), and MO,&-0)&s-S), cores (ii) Non-cubane-ty pe. MO, cores E. Syntheses of dinuclear tungsten compounds (i) W 0 S cores(n=l-4) 2 4-n I (ii) W&S), cores (iii) W(&), W, W(p-S)&S,)W, and W(WS,) cores (iv) W(p.S)W. (O,)W@-S)W(O,), (S,)Wb-S)W(S,), and W(P-S)~ W(S,) cores (v) Miscellaneous F Trinuclear tungsten(IV) compounds (i) W,&-S)(p-X), cores (X = 0, S) (ii) W,(p,-S)(y-S,), cores (iii) Linear W, or W, cores G. Syntheses of cubane-type and incomplete cubane-type mixed-metal compounds ....... Acknowledgements References 16 II II 78 82 82 86 86 90 92 96 100 101 105 105 110 110 112 116 116 116 122 122 122 125 125 125 128 136 136 137 137

Cubane and incomplete cubane-type molybdenum and tungsten oxo/sulfido clusters

Publisher Summary This chapter presents a survey on the structural aspect of cubane-type compounds with Mo 4 O 4– n ,S n ( n = 0, 3, or 4) cores and incomplete cubane-type compounds with Mo 3 O 4– n S, and W 3 O 4– n S n (n = 0-4) cores. Compounds with mixed-metal cubane-type cores Mo 3 MS 4 (M = metals) are also discussed in the chapter. Notes on synthetic procedures are presented. Although the solid-state chemistry of molybdenum has been developed with, for example, infinite repeat MO 3 S 4 units, only discrete compounds with these cores are presented in this chapter. This review has been organized primarily according to the number of Mo and W metals (three or four) and secondarily according to the number of bridging sulfur atoms. In contrast to the situation, many incomplete cubane-type clusters with MO 3 O 4 – n S n cores have been prepared and the structures have been determined by X-ray structure analyses. The results obtained are presented in the chapter. There are three kinds of cubane-type cores in this series of complexes. There is the single cubane-type, Mo 3 MS 4 , the double cubane-type, Mo 3 S 4 MMS 4 Mo 3 , and the sandwich cubane-type, Mo 3 -S 4 MS 4 Mo 3 .

Preparation of trinuclear molybdenum(IV) ion, Mo3S4+4, and x-ray structure of Ca[Mo3S4 {HN(CH2CO2)2}3] · 11.5H2O

Abstract The equilateral trinuclear Mo(IV) ion of incomplete cubane-type structure, Mo3S4+4, was prepared by the reduction of [Mo2O2S2(cys)2]2− with NaBH4 followed by air oxidation and Sephadex G-10 separation. The resultant green solution was analyzed to give S/Mo = 1.33. The spectrum {λmax[e(M−1cm−1)]:367(5190), 500sh(290) and 602(351) in 2 M HPTS} remains unchanged in the air. The existence of the Mo3S4 core has been confirmed by X-ray structure analysis of Ca[Mo3S4(ida)3] · 11.5H2O (H2ida = iminodiacetic acid) which was prepared from the Mo3S4+4 ion and H2ida. Crystal data : orthorhombic, a = 13.815(3) A, b = 26.189(9) A, c = 9.447(3) A, V = 3417.9(17) A3, Z = 4, Dc = 2.053 g cm−3, space group P212121. R value is 0.048 for 3705 reflections [Fo ⩾ 3σ(Fo)]. The anion [Mo3S4(ida)3]2− has an approximate symmetry of C3ν and contains an incomplete cubane-type Mo3S4 core. Selected mean bond distances are as follows: MoMo, 2.754 A, Moμ3-S, 2.349 A; Moμ2-S, 2.295 A; MoO, 2.167 A, MoN, 2.227 A. The existence of an [Mo(IV)]]2Mo(III) oxidation state has been indicated for the first time from the cyclic voltammogram and polarogram of the anion.

Isolation and X-ray structure determination of a sulphur-bridged incomplete cubane-type molybdenum(IV) aqua cluster, [Mo3S4(H2O)9](CH3·C6H4·SO3)4·9H2O

Abstract The title compound was isolated in high yield (72%) from 4 M HPTS solution, and the X-ray crystal structure has been determined. The cluster cation has an approximate C3ν, symmetry. The average MoMo distance (2.735[8] A) in the aqua complex is the shortest reported in complexes with Mo3S4 cores so far. Every SO3− moiety of the pts− anion faces towards the complex cation.

Anti-cancer effects of newly developed chemotherapeutic agent, glycoconjugated palladium (II) complex, against cisplatin-resistant gastric cancer cells

BackgroundCisplatin (CDDP) is the most frequently used chemotherapeutic agent for various types of advanced cancer, including gastric cancer. However, almost all cancer cells acquire resistance against CDDP, and this phenomenon adversely affects prognosis. Thus, new chemotherapeutic agents that can overcome the CDDP-resistant cancer cells will improve the survival of advanced cancer patients.MethodsWe synthesized new glycoconjugated platinum (II) and palladium (II) complexes, [PtCl2 (L)] and [PdCl2 (L)]. CDDP-resistant gastric cancer cell lines were established by continuous exposure to CDDP, and gene expression in the CDDP-resistant gastric cancer cells was analyzed. The cytotoxicity and apoptosis induced by [PtCl2 (L)] and [PdCl2 (L)] in CDDP-sensitive and CDDP-resistant gastric cancer cells were evaluated. DNA double-strand breaks by drugs were assessed by evaluating phosphorylated histone H2AX. Xenograft tumor mouse models were established and antitumor effects were also examined in vivo.ResultsCDDP-resistant gastric cancer cells exhibit ABCB1 and CDKN2A gene up-regulation, as compared with CDDP-sensitive gastric cancer cells. In the analyses of CDDP-resistant gastric cancer cells, [PdCl2 (L)] overcame cross-resistance to CDDP in vitro and in vivo. [PdCl2 (L)] induced DNA double-strand breaks.ConclusionThese results indicate that [PdCl2 (L)] is a potent chemotherapeutic agent for CDDP-resistant gastric cancer and may have clinical applications.

Preparation and X-Ray Structure of Cubane-Type Mixed Metal Aqua Ion, [Mo3NiS4(H2O)10]4+

Abstract We have recently reported that the incomplete cubane-type aqua ion, [Mo3S4(H2O)9]4+ (A), reacts with metals (Fe,1 Cu,2, and Hg3) to give cubane-type mixed metal aqua ions, the core structures of which have been verified by the X-ray structure analyses of the complexes derived from the aqua ions. In addition, it was found that the reaction of A with metallic magnesium gave a double cubane-type aqua ion.4 We now present the preparation, properties, and X-ray structure of a new cubane-type molybdenum-nickel-sulfur mixed metal cluster compound, [Mo3NiS4(H2O)10](CH3°C6H4·SO3)4·6H2O (B), prepared from the aqua ion A and metallic nickel. Mo2Ni2Cp2(CO)2 is the only compound so far reported to have the cubane-type Mo-Ni-S core.5

Uptake of ethylene by sulfur-bridged cubane-type molybdenum/tungsten-nickel clusters [M3NiS4(H2O)10]4+ M3=Mo3, Mo2W, MoW2, W3): syntheses, structures and 1H NMR spectra

Abstract The reaction of the incomplete cubane-type molybdenum/tungsten clusters [M3S4(H2O)9]4+ M3=Mo2W, MoW2, W3 with nickel metal gave the corresponding single cubane-type molybdenum/tungsten-nickel clusters [M3NiS4(H2O)10]4+, respectively. X-ray analyses of the clusters revealed that when pts− was used as the counter anion (Hpts, p-toluenesulfonic acid), the cluster [Mo2WNiS4(H2O)10]4+ (Mo2WNi) crystallized out as the single cubane-type [Mo2WNiS4(H2O)10](pts)4 · 7H2O (Mo2WNipts), and the clusters [MoW2NiS4(H2O)10]4+-(MoW2Ni) and [W3NiS4(H2O)10]4+ (W3Ni) crystallized out as the double cubane-type [{MoW2NiS4(H2O)9}2](pts)8 · 20H2O (MoW2Nipts) and [{W3NiS4(H2O)9}2](pts)8 · 20H2O (W3Nipts), respectively. The crystallographic results obtained are as follows: Mo2WNipts: triclinic, P 1 , a = 17.836(7), b = 19.599(10), c = 8.924(5) A , α = 102.77(5), β = 103.49(4), γ = 63.67(3)° , V = 2694(2) A 3 , Z = 2, R = 5.0%, MoW2Nipts: tricilinic, P 1 , a = 15.413(3), b = 16.743(3), c = 12.073(4) A , α = 96.123(12) , β = 108.39(2), γ = 102.25(2)°, V = 2838(1) A 3 , Z = 1, R = 8.8% ; W3Nipts: tricilinic, P 1 , a = 15.468(5), b = 16.869(5), c = 12.007(3) A , α = 95.61(3), β = 108.71(2), γ = 102.24(3)°, V = 2853(2) A 3 , Z = 1, R = 9.0% . The molybdenum/tungsten-nickel cubane-type clusters [Mo3NiS4(H2O)10]4+ (Mo3Ni), Mo2WNi, MoW2Ni and W3Ni take up ethylene in aqueous or organic solutions to give olefin π-complexes [Mo3NiS4(C2H4)(H2O)9]4+ (Mo3NiEt), [Mo2WNiS4(C2H4)(H2O)9]4+ (Mo2NiEt), [MoW2NiS4(C2H4)(H2O)9]4+ (MoW2NiEt) and [W3NiS4(C2H4)(H2O)9]4+ (W3NiEt), respectively. The reactivity of Mo3Ni with ethylene is not so high as the tungsten containing clusters, Mo2WNi, MoW2Ni and W3Ni, and the reaction does not complete in aqueous solution. However, in organic solutions such as CH2Cl2, the reaction was completed. The following crystals were obtained and X-ray structures were determined: [ Mo 2 WNiS 4 ( C 2 H 4 )( H 2 O ) 9 ]( pts ) 1 2 ·6 HO (Mo2WNiEtpts), [ MoW 2 NiS 4 ( C 2 H 4 )( H 2 O ) 9 ]( pts ) 4 ( Hpts ) 1 2 ·6 H 2 O (MoW2NiEtpts) and [ W 3 NiS 4 ( C 2 H 4 )( H 2 O ) 9 ]( pts ) 4 ( Hpts ) 1 2 · 6 H 2 O (W3NiEtpts). The crystallographic results obtained are as follows: Mo2WNiEtpts: trigonal, P 3 1 c , a = 16.186(6) , c = 27.898(7) A , V = 6330(3) A 3 , Z = 4, R = 6.7% , MoW2NiEtpts; trigonal, P 3 1 c , a = 16.19(2), c = 27.776(4) A , V = 6306(8) A 3 , Z = 4, R = 7.2% ; W3NiEtpts: trigonal, P 3 1 c , a = 16.247(9), c = 27.785(7) A , V = 6352(4) A 3 , Z = 4, R = 7.2% . The X-ray structure analyses revealed that the three clusters are isomorphous with each other and that ethylene coordinates to the nickel site in each cluster. The ethylene molecule on the three-fold axis is disordered, and molybdenum and tungsten atoms in Mo2WNiEt and MoW2NiEt are statistically disordered. 1H NMR spectra of Mo3NiEt, Mo2WNiEt, MoW2NiEt and W3NiEt were obtained. An increase in the number of tungsten atoms in the clusters resulted in an increase in the upfield chemical shift of the 1H NMR signal due to the coordinated ethylene: this tendency can be explained by the fact that tungsten withdraws less electrons than molybdenum, which causes the higher electron density of the hydrogen atoms of ethylene in tungsten-containing clusters. While the nickel complexes so far reported which are reactive toward ethylene contain zero-valent nickel, the formal oxidation state of the nickel atoms in the clusters Mo3Ni, Mo2WNi, MoW2Ni and W3Ni is two, which is evident from the XPS data of Ni 2 p 3 2 Ni metal, 852.7; Mo3Ni, 854.7; Mo2WNi, 854.6; W3Ni, 854.5 eV.

Oxo- and sulfido-bridged sandwich cubane-type molybdenum-indium mixed-metal cluster. Synthesis and X-ray structure of [(H2O)9Mo3S3OInOS3Mo3-(H2O)9](CH3·C6H4·SO3)8·3OH2O

Abstract The aqua cluster [Mo3(μ3-S)(μ-O)(μ-S)2(H2O)9]4+ (B) reacts with indium metal in aqueous solution of Hpts to give a novel sandwich cubane-type molybdenum-indium mixed- metal cluster [(H2O)9Mo3S3OInOS3Mo3(H2O)9]8+ (C). The cluster C is oxidized in hydrochloric acid to give the starting species B, evolution of hydrogen gas being detected. An intermediate is isolated, and is tentatively assigned to Mo3In(μ3-S)(μ-O)(μ-S)25+(aq) (D). The following reaction pathways are proposed: 2B+In→C; C+H+→D+B+ 1 2 H2; D+2H+→B+In3++H2.

Molybdenum–copper–sulfur Mo3CuS4 cubes

Abstract Reaction of the incomplete cubane-type cluster [Mo3S4(H2O)9]4+ (1) with CuCl in 2 M HCl gives a novel cubane-type cluster [Mo3CuS4Cl(H2O)9]4+ (2). The nitrilotriacetato complex [Mo3CuS4Cl(Hnta)3]2− (3), the derivative of 2, has been prepared. The crystallographic results obtained were as follows: K2[Mo3CuS4Cl(Hnta)3]·9H2O (3a), triclinic, P1, a=10.634(1), b=11.032(2), c=10.299(4) A, α=112.34(2), β=98.76(2), γ=81.91(1)°, V=1100.3(4) A3, Z=1, R=5.7%; (NH4)2[Mo3CuS4Cl(Hnta)3]·9H2O (3b), triclinic, P1, a=10.714(1), b=11.121(1), c=10.379(3) A, α=112.07(1), β=99.375(8), γ=81.168(7)°, V=1124.9(4) A3, Z=1, R=8.3%; (NH4)2[Mo3CuS4Cl(Hnta)3]·9H2O (3c) trigonal, R3m, a=16.332(2), c=14.301(2) A, V=3303.5(4) A3, Z=3, R=4.2%. Binding energies of Cu 2p3/2, Cu 2p1/2, Mo 3d5/2, and Mo 3d3/2 from X-ray photoelectron spectroscopy measurements are 933.35, 953.26, 230.07 and 233.24 eV for 3a, 933.47, 953.25, 230.18 and 233.31 eV for 3b, respectively (C1s=285.0 eV). The binding-energy values of Cu 2p3/2 for 3a and 3b and the absence of satellites indicate the Cu(I) oxidation state in the respective clusters. The comparison of [Mo3CuS4Cl(H2O)9]4+ (2) in hydrochloric acid with [Mo3CuS4(H2O)10]5+ (2′) in Hpts reveals that the coordination of chloride ion to copper atom increases very much the stability of 2 in hydrochloric acid solution. Air oxidation of [Mo3CuS4Cl(H2O)9]3+ (4) and [Mo3CuS4(H2O)10]4+ (4′) and the reaction and reaction products of [Mo3FeS4(H2O)10]4+ (5) with Cu(II) ion will be discussed.

Syntheses of sulfur-bridged tungsten(V) complexes with syn-W2O2S2 cores. X-ray structures of K2[W2O2S2(cys)2]·5H2O and NaNH4[W2O2S2(edta)]·2H2O

Abstract Facile synthetic methods for sulfur-bridged tungsten(V) dimers, [W2O2S2(cys)2]2−1 are described, which were obtained directly from sodium tungstate, sodium sulfide, and L -cysteine, together with the description of another route to [W2O2S2(cys)2]2− using ammonium tetrathiotungstate and L -cysteine. Synthetic methods for the derivative compounds, W2O2S22+(aq) and [W2O2S2(edta)]2− are also described. The X-ray structures of two compounds are determined. The compound K2[W2O2S2(cys)2]·5H2O (1) crystallizes in the monoclinic space group P21, a=9.670(1), b=15.993(2), c=6.893(1) A, β=95.02(1)°, V=1062.0(3) A3, Z=2, R=2.76%. The compound NaNH4[W2O2S2(edta)]·2H2O crystallizes in monoclinic P21/a, a=24.522(8), b=12.395(6), c=7.098(2) A, β=104.21(3)°, V=2091.5(14) A3, Z=4, R=4.24%. The complex anions [W2O2S2(cys)2]2− and [W2O2S2(edta)]2− have an approximate symmetry of C2 and contain the core syn-W2(Ot)2(μ-S)2.