Transition metal-promoted carbon-carbon bond formation by reductive dimerization of carbon disulfide: direct synthesis of the bis(1,2-dithiolene-like) tetrathiooxalato (C2S4) ligand from carbon disulfide by reaction with the dimeric nickel(I) complexes Ni2(.eta.5-C5R5)2(.mu.-CO)2 (R = H, Me)

Abstract

Although intensive efforts have been devoted during recent years to prepare and characterize metal-bound C02 complexes in conjunction with C02 fixation via reactions with transition-metal systems,2 only a few metal-coordinated C02 complexes have been isolated and crystallographically ascertained.3"6 These include a novel d6 Ir(III) IrCl(C204)(PMe3)3 product6 in which the C204 ligand has been formed from a head-to-tail 02C-0C0 dimerization of C02 by initial reaction with a d8 Ir(I) complex. On the other hand, the more reactive, related cumulene (or heteroallene) carbon disulfide has been shown from structural studies2,7,8 to

CC Bond Formation through Reductive Coupling of CS2 to Yield Uranium Tetrathiooxalate and Ethylenetetrathiolate Complexes

“…In accordance with a two-electron reduction process, the bond order increases to a C=C double bond as indicated in the C55ÀC55' bond of 1.383 (8) that is comparable to reported ethylenetetrathiolate complexes. [13,16,17] The C55 À S1 and C55 À S2 bond lengths (1.789(4) and 1.766(4) ) in 3 and longer than in 2 and in other ethylenetetrathiolate complexes (ca. 1.70-1.76 ).…”

“…[11,12] Recently, a Sm II complex was reported to undergo CÀS reductive coupling of CS 2 to yield [(Giso) 2 Sm(mh 2 :h 2 -S 2 CSCS)Sm(Giso) 2 ] (Giso = [(ArN) 2 CNCy 2 ], Ar = 2,6diisopropylphenyl, Cy = cyclohexyl). [22] To date, reductive head-to-head coupling of CS 2 has resulted only in formation of ethylenetetrathiolate (C 2 S 4 4À ) [13,14,16,17] or C 2 S 4 4À -like thiooxalate complexes. [15] Compared to the CÀC s-bond in oxalate dianion C 2 O 4 2À , the CÀC s-bond in C 2 S 4 is relatively weak.…”

“…Generation of trithiocarbonate complexes from CS 2 has been well-documented. [8][9][10] However, the formation of C 2 S 4 nÀ units from the reductive coupling of CS 2 is uncommon [11][12][13][14][15][16][17] despite C 2 S 4 ligands being implicated as the conducting units in multimetallic complexes. [18][19][20] Unlike dianionic C 2 O 4 2À…”

C‐C‐Bindungsknüpfung durch reduktive Kupplung von CS2 an Uran zur Bildung von Tetrathiooxalat‐ und Ethylentetrathiolatkomplexen

“…[11,12] Kürzlich wurde über einen Sm II -Komplex berichtet, der durch reduktive CS 2 -Kupplung zum Komplex [(Giso) 2 Sm(m-h 2 :h 2 -S 2 CSCS)Sm(Giso) 2 ] (Giso = [(ArN) 2 CNCy 2 ], Ar = 2,6-Diisopropylphenyl, Cy = Cyclohexyl) führte. [22] Durch reduktive Kopf-Kopf-Kupplung (C-C-Bindungsknüpfung) von CS 2 konnten bislang nur Ethylentetrathiolat (C 2 S 4 4À ) [13,14,16,17] oder C 2 S 4 4À -artige Thiooxalatkomplexe [15] hergestellt werden. Verglichen mit der C-C-s-Bindung im Oxalat-Dianion C 2 O 4 2À ist die C-C-s-Bindung in C 2 S 4 relativ schwach.…”

“…Dieser Wert ist vergleichbar mit den Bindungslängen anderer Ethylentetrathiolatkomplexe. [13,16,17] Die C55-S1-und C55-S2-Bindungen (1.789(4) und 1.766(4) ) sind in 3 länger als in 2 und anderen Ethylentetrathiolatkomplexen (1.70-1.76 ). [13,16,17] Die temperaturabhängigen SQUID-Magnetisierungsdaten von 2 und 3 sind einander recht ähnlich.…”