@misc{oai:ir.soken.ac.jp:00000160,
 author = {小江, 誠司 and オゴウ, セイジ and OGO, Seiji},
 month = {2016-02-17, 2016-02-17},
 note = {The purposes of this thesis are to develop a systematically synthetic method of higher-nuclearity heterometallic sulfide clusters, to investigate interactions of M-S-M' (M and M' = Rh, W, or Cu) groups in the newly prepared clusters, and to find an interesting reactivity of the M-S-M' groups in the clusters toward small molecules (e.g. H20 and H2S) from view points of a basic cluster chemistry.
  Most clusters prepared in this research have been obtained by a unique building　block method as a rationally synthetic approach in which an organorhodium group (Cp*RhP(OEt)3, Cp* = η5 -C5 Me5) plays an important role to prevent from polymerizing of the products and to construct the higher-nuclearity heterometallic sulfide clusters soluble in common organic solvents.
  In Chapter 1 the building-block approach toward a stepwise synthesis, [Cp*RhP(OEt)3 Cl2] (1) → [Cp*RhP(OEt)3 WS4] (2) → [Cp*RhP(OEt)3 (μ-WS4 )CuCl] (3) → [{Cp*RhP(OEt)3(μ-WS4)(CuCl)Cu}2(μ-Cl)2] (4), and as well as 1 → [{Cp*RhP(OEt)3}2 (μ-WS4)][BPh4]2 (5-[BPh4]2), is demonstrated.  The structures　of 1, 2, 3, 4, and 5-[BPh4]2 were confirmed by X-ray diffraction analysis.  The formation and structures of 3 and 4 have the following characteristics: the trinuclear sulfide cluster 3 possesses a linear sequence of Rh, W, and Cu atoms with octahedral, tetrahedral, and trigonal planar coordination geometries, respectively.  Although there　are three presumed geometrical isomers for 3 based on the difference in the binding site of CuCl on the WS4 core, the reaction between 2 and CuCl gave specifically 3 in nearly quantitative yield because the specific formation of 3 is due to the strong coordination ability of the terminal S atoms in 2 (see Scheme 1).  The linear-type framework of 3 is preserved in dichloromethane and acetonitrile solutions.
 As shown in Scheme 1 cluster 4 has an octanuclear framework with a crystallographic inversion center, and the eight metal atoms are arranged in a branched  configuration in which Rh…W…Cu1 is almost linear (172.43ﾟ) and Rh…W…Cu2 is an approximately right angle (90.73ﾟ).  The X-ray results indicate that cluster 3 performs a regiospecific CuCl-addition at S1 (or S1*) and S2 atoms to form 4.  This regiospecific addition is attributed mainly to a steric demand of the Cp* and P(OEt)3 ligands.  In dichloromethane cluster 4 exists as a tetranuclear species, [{Cp*RhP(0Et)3 (μ-WS4)(CuCl)2], however, in acetonitrile exists as 3 and the freed CuCl.
  In Chapter 2 a unique conversion of a bridging S atom of 4 to a terminal 0 atom of [Cp*RhP(0Et)3 (μ-WOS3)(CuCl)Cu}2 (μ-Cl)2] (8) by the water saturated in dichloromethane is described.  This is the first example of the conversion of the bridging S atom in the M-S-M' groups into the terminal O atom without releasing the metal atoms.  The use of the water saturated in dichloromethane is essential, because the several attempts to obtain 8 from 4 by using aqueous acetonitrile, basic conditions in common solvents, and two-phase conditions of water and dichloromethane which gave 1, 3, [Cp*RhP(0Et)3 (μ-WOS3)(CuCl)] (7), and other unidentified products were not successful.  On the other hand, clusters 2 and 3 are little reacted with the water saturated in dichloromethane or water under two-phase conditions of water and dichloromethane in contrast to 4.  It seems that the specific reactivity of the W-S-Cu groups of 4 is dependent on differences in electron densities of the S atoms and steric effects of the Cp* and P (OEt)3 groups.  A tentative mechanism of the transformation reaction, 4 → 8, can be assumed as follows: water molecule interacts with the W atom and the S atom that has the high electron density in the four S atoms of the μ-WS4 group of 4 to give an intermediary species that has W-0-H and Cu-S-H groups, and then the species is transformed to 8.
  Cluster 8 was also obtained by a stepwise synthesis using [WOS3]2- as a tungsten source:  1 → [Cp*RhP(OEt)3 (μ-S)2 W0S] (6a) → 7 → 8.  Cluster 6a is one of two possible geometrical isomers of [Cp*RhP(OEt)3 (μ-S)2 W0S].  The structures of 7 and 8 were determined by X-ray analysis.  In addition the reactions of 4, 7, and 8 with hydrogen sulfide to give 3 as the only major product are studied in Chapter 2.
  In Chapter 3 it was investigated whether fast atom bombardment mass spectrometry (FAB-MS) provides useful information about higher-nuclearity sulfide clusters, which may be synthesized by a direct synthetic method.  The FAB mass spectrum of the linear trinuclear sulfide cluster 3 shows many ions heavier than the molecular ion.  One envelope corresponds to a pentanuclear sulfide cluster, [{Cp*RhP(OEt)3 (μ-WS4)} 2Cu]+  ([B]+ ).  It was synthesized by the reaction between cluster 2 and Cu+ in a 2:1 molar ratio to yield the compound, [{Cp*RhP(OEt)3 (μ-WS4 )} 2Cu][PF6 ] (9･[PF6 ]).  The structure was determined by a combination of single-crystal X-ray diffraction analysis, Extended X-ray absorption fine structure (EXAFS), and IR measurements. The FAB mass spectrum of 9[PF6+] showed that the cationic cluster [9]+ is identical with [B]+ found in the FAB mass spectrum of 3.  Thus this result suggests that the FAB-MS technique provides useful guiding principal for synthesis of higher nuclearity clusters., application/pdf, 総研大甲第180号},
 title = {Synthesis of Novel Higher-Nuclearity Heterometallic Sulfide Clusters by a Building Block Method},
 year = {}
}