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Sarker JC, Nash R, Boonrungsiman S, Pugh D, Hogarth G. Diaryl dithiocarbamates: synthesis, oxidation to thiuram disulfides, Co(III) complexes [Co(S 2CNAr 2) 3] and their use as single source precursors to CoS 2. Dalton Trans 2022; 51:13061-13070. [PMID: 35972272 DOI: 10.1039/d2dt01767a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Air and moisture stable diaryl dithiocarbamate salts, Ar2NCS2Li, result from addition of CS2 to Ar2NLi, the latter being formed upon deprotonation of diarylamines by nBuLi. Oxidation with K3[Fe(CN)6] affords the analogous thiuram disulfides, (Ar2NCS2)2, two examples of which (Ar = p-C6H4X; X = Me, OMe) have been crystallographically characterised. The interconversion of dithiocarbamate and thiuram disulfides has also been probed electrochemically and compared with that established for the widely-utilised diethyl system. While oxidation reactions are generally clean and high yielding, for Ph(2-naphthyl)NCS2Li an ortho-cyclisation product, 3-phenylnaphtho[2,1-d]thiazole-2(3H)-thione, is also formed, resulting from a competitive intramolecular free-radical cyclisation. To demonstrate the coordinating ability of diaryl dithiocarbamates, a small series of Co(III) complexes have been prepared, with two examples, [Co{S2CN(p-tolyl)2}3] and [Co{S2CNPh(m-tolyl)}3] being crystallographically characterised. Solvothermal decomposition of [Co{S2CN(p-tolyl)2}3] in oleylamine generates phase pure CoS2 nanospheres in an unexpected phase-selective manner.
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Affiliation(s)
- Jagodish C Sarker
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK. .,Department of Chemistry, Jagannath University, Dhaka-1100, Bangladesh
| | - Rosie Nash
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK.
| | - Suwimon Boonrungsiman
- Centre for Ultrastructural Engineering, King's College London, New Hunt's House, London SE1 1UL, UK
| | - David Pugh
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK.
| | - Graeme Hogarth
- Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK.
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Fontenot PR, Shan B, Wang B, Simpson S, Ragunathan G, Greene AF, Obanda A, Hunt LA, Hammer NI, Webster CE, Mague JT, Schmehl RH, Donahue JP. Photocatalytic H 2-Evolution by Homogeneous Molybdenum Sulfide Clusters Supported by Dithiocarbamate Ligands. Inorg Chem 2019; 58:16458-16474. [PMID: 31790221 DOI: 10.1021/acs.inorgchem.9b02252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Irradiation at 460 nm of [Mo3(μ3-S)(μ2-S2)3(S2CNR2)3]I ([2a]I, R = Me; [2b]I, R = Et; [2c]I, R = iBu; [2d]I, R = CH2C6H5) in a mixed aqueous-polar organic medium with [Ru(bipy)3]2+ as photosensitizer and Et3N as electron donor leads to H2 evolution. Maximum activity (300 turnovers, 3 h) is found with R = iBu in 1:9 H2O:MeCN; diminished activity is attributed to deterioration of [Ru(bipy)3]2+. Monitoring of the photolysis mixture by mass spectrometry suggests transformation of [Mo3(μ3-S)(μ2-S2)3(S2CNR2)3]+ to [Mo3(μ3-S)(μ2-S)3(S2CNR2)3]+ via extrusion of sulfur on a time scale of minutes without accumulation of the intermediate [Mo3S6(S2CNR2)3]+ or [Mo3S5(S2CNR2)3]+ species. Deliberate preparation of [Mo3S4(S2CNEt2)3]+ ([3]+) and treatment with Et2NCS21- yields [Mo3S4(S2CNEt2)4] (4), where the fourth dithiocarbamate ligand bridges one edge of the Mo3 triangle. Photolysis of 4 leads to H2 evolution but at ∼25% the level observed for [Mo3S7(S2CNEt2)3]+. Early time monitoring of the photolyses shows that [Mo3S4(S2CNEt2)4] evolves H2 immediately and at constant rate, while [Mo3S7(S2CNEt2)3]+ shows a distinctive incubation prior to a more rapid H2 evolution rate. This observation implies the operation of catalysts of different identity in the two cases. Photolysis solutions of [Mo3S7(S2CNiBu2)3]+ left undisturbed over 24 h deposit the asymmetric Mo6 cluster [(iBu2NCS2)3(μ2-S2)2(μ3-S)Mo3](μ3-S)(μ3-η2,η1-S',η1-S″-S2)[Mo3(μ2-S)3(μ3-S)(S2CNiBu2)2(μ2-S2CNiBu2)] in crystalline form, suggesting that species with this hexametallic composition and core topology are the probable H2-evolving catalysts in photolyses beginning with [Mo3S7(S2CNR2)3]+. When used as solvent, N,N-dimethylformamide (DMF) suppresses H2-evolution but to a greater degree for [Mo3S4(S2CNEt2)4] than for [Mo3S7(S2CNEt2)3]+. Recrystallization of [Mo3S4(S2CNEt2)4] from DMF affords [Mo3S4(S2CNEt2)4(η1,κO-DMF)] (5), implying that inhibition by DMF arises from competition for a Mo coordination site that is requisite for H2 evolution. Computational assessment of [Mo3S4(S2CNMe2)3]+ following addition of 2H+ and 2e- suggests a Mo(H)-μ2(SH) intermediate as the lowest energy species for H2 elimination. An analogous pathway may be available to the Mo6 cluster via dissociation of one end of the μ2-S2CNR2 ligand, a known hemilabile ligand type, in the [Mo3S4]4+ fragment.
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Affiliation(s)
- Patricia R Fontenot
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Bing Shan
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Bo Wang
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Spenser Simpson
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Gayathri Ragunathan
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Angelique F Greene
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Antony Obanda
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Leigh Anna Hunt
- Department of Chemistry and Biochemistry , University of Mississippi , Oxford , Mississippi 38655 , United States
| | - Nathan I Hammer
- Department of Chemistry and Biochemistry , University of Mississippi , Oxford , Mississippi 38655 , United States
| | - Charles Edwin Webster
- Department of Chemistry , Mississippi State University , P.O. Box 9573, Mississippi State , Mississippi 39762-9573 , United States
| | - Joel T Mague
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - Russell H Schmehl
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
| | - James P Donahue
- Department of Chemistry , Tulane University , 6400 Freret Street , New Orleans , Louisiana 70118-5698 , United States
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