| 1. |
- Ahmed, SJ, et al.
(författare)
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Dppm-substituted ruthenium clusters with capping sulfido and selenido ligands derived from thiourea, tetramethylthiourea and elemental selenium
- 2006
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 691:3, s. 309-322
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Tidskriftsartikel (refereegranskat)abstract
- Treatment of [Ru-3(CO)(10)(mu-dppm)] (4) [dppm = bis(diphenylphosphido)methane] with tetramethylthiourea at 66 degrees C gave the previously reported dihydrido triruthenium cluster [Ru-3(mu-H)(2)(mu(3)-S)(CO)(7)(mu-dppm)] (5) and the new compounds [Ru-3(mu(3)-S)(2)(CO)(7)(mu-dppm)] (6), [Ru-3(mu(3)-S)(CO)(7)(mu(3)-CO)(mu-dppm)] (7) and [Ru-3(mu 3-S)eta(I)-C(NMe2)(2)}(CO)(6)(mu(3)-CO)(mu-dppm)] (8) in 6%, 10%, 32% and 9% yields, respectively. Treatment of 4 with thiourea at the same temperature gave 5 and 7 in 30% and 10% yields, respectively. Compound 7 reacts further with tetramethylthiourea at 66 degrees C to yield 6 (30%) and a new compound [Ru-3(mu(3)-S)(2){mu(3)-C(NMe2)(2)}(CO)(6)(mu-dppm)] (9) (8%). Thermolysis of 8 in refluxing THF yields 7 in 55% yield. The reaction of 4 with selenium at 66 degrees C yields the new compounds [Ru-3(mu(3)-Se)(CO)(7)(mu(3)-CO)(mu-dppm)] (12) and [Ru-4(mu(3)-Se)(mu(3)-eta(3)-PhPCH2PPh(C6H4)(CO)(6)(mu-CO)] (11) and the known compounds [Ru-3(mu-H)(2)(mu(3)-Se)(CO)(7)(mu-dppm)] (12) and [Ru-4(mu(3)-Se)(4)(CO)(6)(mu-dppm)] (13) in 29%, 5%, 2% and 5% yields, respectively. Treatment of 10 with tetramethylthiourea at 66 degrees C gives the mixed sulfur-selenium compounds [Ru-3(mu(3)-S)([mu(3)-Se)(CO)(7)(mu-dppm)] (14) and [Ru-3(mu(3)-S)(mu(3)-Se){eta(1)-C(NMe2)(2)}(CO)(6)(mu-dppm)] (15) in 38% and 10% yields, respectively. The single-crystal XRD structures of 6, 7, 8, 10, 14 and 15 are reported.
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| 2. |
- Akter, H, et al.
(författare)
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Triphenylphosphine-substituted selenido and sulfido clusters of osmium derived from Ph3P=Se or Ph3P=S
- 2005
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 690:21-22, s. 4628-4639
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Tidskriftsartikel (refereegranskat)abstract
- Cleavage of P=Se bonds occurs readily in the room-temperature treatment of [Os-3(CO) (10)(MeCN)(2)] with Ph3P=Se to give three new compounds, [Os-3(mu(3)-Se)(2)(CO)(8)(PPh3)] (2), [Os-3(mu(3)-Se)( mu(3)-CO)(CO)(7)(PPh3)(2)] (5) and [Os3(mu-OH)(2)(CO)(8)(PPh3)(2)] (6), respectively, and three known compounds, [Os-3(mu(3)-Se)(2)(CO)(9)] (1), [Os-3(mu(3)-Se)(mu-CO)(2)(CO)(7)(PPh3)] (3), and 1,2-[Os-3(CO)(10)(PPh3)(2)] (4). No evidence for any product containing a co-ordinated Ph3P--Se ligand was obtained. The analogous reaction between [OS3(CO)10(MeCN)2] and Ph3P=S produces five new compounds [Os-3(mu(3)-S)(2)(CO)(8)(PPh3)] (7), [Os-3(mu(3)-S)(mu-CO)(2)(CO)(7)(PPh3)] (8), [Os-3(mu(3)-S) (mu(3)- CO)(CO)(7)(PPh3)(2)] (9), [Os-3(mu(3)-)(2)(CO)(7)(PPh3)(2)] (11) and compound 6 in addition to the known compound 4. Treatment of with Me3NO at 50 degrees C gives the trinuclear cluster [Os-3(mu(3)-Se)(2)(CO)(7)(PPh3)(NMe3)] (13) and the hexanuclear cluster [Os-6(mu(3)-Se)(4)(CO)(14) (PPh3)(2)] (12). Treatment of compound 1 with PPh3 and Me3NO at room temperature gives [Os-3(mu(3)-Se)(2)(CO)(7)(PPh3)(2)] (10). Compound 2 reacts with PPh3 similarly to give 10. Compound 3 reacts with elemental selenium at 110 degrees C to give 2. The new compounds 2, 5, 6 and 8 were characterized by single-crystal X-ray diffraction. The compounds 3, 5, 8 and 9 contain Os-3(mu(3)-S) or Os-3(mu(3)-Se)cluster cores with three metal-metal bonds while 2, 7, 10, 11 and 12 contain Os-3(mu(3)-S)(2) or Os(mu(3)-Se)(2) cores two metal-metal bonds. The two hydroxy ligands in the triosmium cluster 6 bridging the open osmium-osmium edge and are probably derived from water. A study of the dynamic exchange of PPh3 ligands in 5 is also reported.
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| 3. |
- Deeming, AJ, et al.
(författare)
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Mechanisms of concurrent hydride migration processes in a triruthenium cluster capped by a phenylphosphinidene (PPh) ligand
- 2005
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Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1099-0682 .- 1434-1948. ; :21, s. 4352-4360
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Tidskriftsartikel (refereegranskat)abstract
- Two methods were used to synthesise [Ru-3(mu-H)(2)(mu(3)-PPh)-(CO)(7) (mu-dppm)] (3) (dppm = Ph2PCH2PPh2), the subject of this paper. Treatment of [Ru-3(CO)(10)(mu-dppm)] (1) with phenylphosphane in refluxing THF gave both [Ru-3(mu-H)(2)(mu-PHPh)-(CO)(8)(mu-dppm)] (2) and [Ru-3(mu-H)(2)(mu(3)-PPh)(CO)(7)(mu-dppm)] (3). Cluster 2 converts to 3 in refluxing THF. Alternatively the phenylphosphinidene cluster [Ru-3(mu-H)(2)(mu(3)-PPh)(CO)(9)] (4), prepared by the reported method of treating [Ru-3(CO)(12)] with phenylphosphane, reacts with dppm to produce cluster 3. The single-crystal X-ray structures of 2 and 3 are reported. Hydride mobility in [Ru-3(mu-H)(2)(mu(3)-PPh)(CO)(7)(mu-dppm)] (3) was analysed by variable-temperature H-1 and P-31(H-1) NMR methods. The variations in the spectra with temperature could not be interpreted by a single process, several of which were explored and which gave inadequately matching computed and experimental spectra. However, the spectra were successfully analysed by two concurrent processes, both involving the migration of hydride ligands between Ru-Ru edges. The faster process leads to the exchange of the nonequivalent phosphorus nuclei but not hydride exchange, whereas the hydrides are also exchanged in the slower process. Both processes require hydride ligand migration from one Ru-Ru edge to a vacant one. The hydride ligand bridging the same pair of ruthenium atoms as the dppm ligand is the slower to migrate.
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| 4. |
- Stchedroff, MJ, et al.
(författare)
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Synthesis, characterisation and natural abundance Os-187 NMR spectroscopy of hydride bridged triosmium clusters with chiral diphosphine ligands
- 2006
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Ingår i: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693. ; 359:3, s. 926-937
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Tidskriftsartikel (refereegranskat)abstract
- Treatment of [Os-3(mu-H)(2)(CO)(10)] with the chiral diphosphines BINAP, tolBINAP [(R)-2,2'-bis(di-4-tolylphosphino)-1,1'-binaphthyl], DIOP [(4R,5R)-(-)-O-isopropenylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino) butane] affords [Os-3(mu-H)(2)(CO)(8)(mu-L)] (L = BINAP (1), tolBINAP (2), DIOP (4)) in high yield. The X-ray structures for 1, 2 and 4 are reported, and structural and spectroscopic comparisons are made between these clusters and [Os-3(mu-H)(2)(CO)(8)(mu-L)] (L = dppm (5), dppe (6), dppp (7)) which were synthesised similarly. Compounds 5 to 7 were previously synthesised by hydrogenation of 1,2-[OS3(CO)(10)(mu-L)] but the route from [Os(mu-H)(2)(CO)(10)] is preferable. The H-bridged Os center dot center dot Os distances are similar in 1, 2 and 4 indicating that these species are formally unsaturated 46-electron clusters. The P center dot center dot center dot P distances vary from 4.24 to 4.30 angstrom in 1 and 2, respectively, to 4.53 angstrom in 4 and there are related changes in the angles associated with the ligand set around the H-bridged osmium atoms. Introduction of the diphosphine ligands completely suppresses the ability to add CO, to insert acetylene to form a mu-eta(1), eta(2)-vinyl compound, and to exchange hydride ligands with styrene-d(8), which are reactions characteristic of [Os-3(mu-H)(2)(CO)(10)], Clusters 2 and 5-7 were also used to examine the potential of natural abundance Os-187 NMR spectroscopy through techniques based on inverse detection by HMQC, HSQC and HMBC spectroscopy. (c) 2005 Elsevier B.V. All rights reserved.
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