Monomeric and dimeric ruthenium thiooxalate complexes: Structures of CpRu(PPh 3 ) 2 SCOCO 2 Me and CpRu(dppe)SCOCO 2 Et Mohammad El-khateeb a, * , Khaled Shawakfeh a , Tobias Ru ¨ffer b , Heinrich Lang b a Chemistry Department, Jordan University of Science and Technology, Irbid 22110, Jordan b Technische Universita ¨ t Chemnitz, Institut fu ¨ r Chemie, Lehrstuhl Anorganische Chemie, Strasse der Nationen 2, Chemnitz 09111, Germany Received 29 March 2006; received in revised form 11 May 2006; accepted 11 May 2006 Available online 20 May 2006 Abstract The hydrosulfido complexes CpRu(L)(L 0 )SH react with one equivalent of O-alkyl oxalyl chlorides (ROCOCOCl) to form the corre- sponding O-alkylthiooxalate complexes CpRu(L)(L 0 )SCOCO 2 R (L = L 0 = PPh 3 (1), 1 2 dppe (2); L = PPh 3 ,L 0 = CO (3); R = Me (a), Et (b)). The reactions of the hydrosulfido complexes with half equivalent of oxalyl chloride produce the bimetallic complexes [CpRu(L)(L 0 )SCO] 2 (L = L 0 = PPh 3 (4), 1 2 dppe (5); L = PPh 3 ,L 0 = CO (6)). The crystal structures of CpRu(PPh 3 ) 2 SCOCO 2 Me (1a) and CpRu(dppe)SCOCO 2 Et (2b) are reported. Ó 2006 Elsevier B.V. All rights reserved. Keywords: Ruthenium; O-alkylthiooxalate; Sulfur; Triphenylphosphine; Diphenylphosphinoethane; Carbonyl; Complexes; Solid-state structure 1. Introduction The coordination chemistry and reactivity of hydrosulf- ido metal complexes, [M]–SH, are of current interest because of their structural diversity, relevant to metalloen- zymes and industrial processes such as hydrodesulfuriza- tion and Claus chemistry [1–4]. The reaction of these hydrosulfido complexes with sulfur dioxide (to give [M]- SS(O)OH) has been proposed as a key step in the Claus process [5,6] and also in the hydrogenation of sulfur diox- ide [7,8]. The bis(triphenylphosphine) hydrosulfido ruthenium complex CpRu(PPh 3 ) 2 SH is prepared by a metathesis reac- tion of the corresponding ruthenium chloride with NaSH [9,10]. Treatment of this hydrosulfido complex with CO gas at room temperature produces the mixed carbonyl- phosphine complex CpRu(PPh 3 )(CO)SH in good isolated yield [9]. The chelate complexes CpRu(dppe)SH and CpRu(dppm)SH have been also reported of which the first one was prepared by a one-pot reaction of CpRu(PPh 3 ) 2 Cl, dppe and NaSH, while the second one is accessible from CpRu(dppm)Cl and NaSH [11]. The ruthenium hydrosulfido complexes CpRu(L)(L 0 )SH are quite reactive toward a variety of electrophiles [10–12]. The reaction of CpRu(PPh 3 ) 2 SH with carbon disulfide is reported to produce the bimetallic complex CpRu(PPh 3 )- (j 2 S,S-S 2 C)SRu(PPh 3 ) 2 Cp via insertion of CS 2 into the Ru–S bond to give CpRu(PPh 3 )(j 2 S,S-S 2 CSH) followed by its reaction with another equivalent of CpRu(PPh 3 ) 2 SH [10]. On the other hand, complexes CpRu(L)(L 0 )SH (L = L 0 = PPh 3 , 1 2 dppm; 1 2 dppe) give with acid chlorides at low temperature the corresponding thiocarboxylate com- plexes CpRu(L)(L 0 )SCOCH 2 -4-C 6 H 4 X (X = H, Me, OMe, Cl) [12]. The mixed carbonyl-phosphine analogs CpRu(PPh 3 )(CO)SCOCH 2 -4-C 6 H 4 X have been prepared by the reaction of CpRu(PPh 3 ) 2 SCOCH 2 -4-C 6 H 4 X with CO [12]. The reaction of the chelate hydrosulfido com- plexes CpRu(dppa)SH (dppa = dppm, dppe) with various sulfonyl chlorides afforded the expected thiosulfonato spe- cies CpRu(L)(L 0 )SSO 2 R [13]. Recently, the reaction of these hydrosulfido complexes with chloroformates 0022-328X/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jorganchem.2006.05.018 * Corresponding author. Tel.: +962 2 7201000; fax: +962 2 7095014. E-mail address: kateeb@just.edu.jo (M. El-khateeb). www.elsevier.com/locate/jorganchem Journal of Organometallic Chemistry 691 (2006) 3743–3748