Walter K. Dean

Reactions of iron carbonyl complexes with dimethylthiocarbamoyl chloride

Abstract The reactions of dimethylthiocarbamoyl chloride with a number of neutral and ionic iron carbonyl complexes in tetrahydrofuran are described. A variety of unusual products were obtained, viz. Fe(CO)2(S2CNMe2)2 from Fe(CO)5; Fe(CO)2(S2CNMe2)(CSNMe2) from Fe2)CO)9, Fe3(CO)12, and Fe(CO)42−; [Fe-(CO)2(S2CNMe2)(CNMe2)(CNMe2)2S]+ from Fe(CO)42−, and Fe4(CO)12S(CSNMe2)-(CNMe2) from Fe2(CO)82−, as well as Fe2(CO)6(CSSEt)2 from Fe2(CO)9 and ClCSSEt. The structures and behavior and some reactions of these complexes are described.

Simplex Optimization of Reaction Yields

The sequential simplex algorithm, an efficient optimization strategy, rapidly improved reaction yield as a function of time and temperature in the synthesis of π-C5H5Mo(CO)2CSN(CH3)2. The work demonstrates the feasibility and efficiency of the simplex design and suggests its application and usefulness in other syntheses.

A complex with a bridging thiocarboxamido group: the crystal structure of Fe4(CO)12S(CSNMe2)(CNMe2)

Abstract The structure of the compound Fe 4 (CO) 12 S(CSNMe 2 )(CNMe 2 ) has been determined by X-ray crystallography. The compound crystallizes in space group P 2 1 / c with four molecules in a unit cell of dimensions a 8.840(2), b 20.174(9), c 16.856(5)A, β 114.82(3)°. Full-matrix least-squares refinement of 2881 counter data yielded R = 0.046. The molecule consists of two Fe 2 (CO) 6 units bridged by thiocarboxamido and immoniocarbene ligands and by a common bridging sulfur atom. The structure of this compound is compared with those of related molecules and a detailed comparison is made of the bonding properties of the thiocarboxamido ligand in bridging and chelating configurations.

The crystal structure of dicarbonyl(dimethylthiocarboxamido)dimethyldithiocarbamatoiron, Fe(CO)2(CSNMe2)(S2CNMe2)

Abstract The crystal structure of Fe(CO)2(CSNMe2)(S2CNMe2) has been determined by X-ray crystallography. The compound crystallizes with four molecules in a unit cell of space group P21/c and dimensions a 13.448(6), b 7.066(2), c 14.590(4) A, β 98.40(3)°. The molecule contains separate dimethyldithiocarbamate and chelating thiocarboxamido ligands in a highly distorted octahedral complex. The FeC distance to the thiocarboxamido ligand is quite short (1.876 A), indicating a considerable degree of π-interaction between these atoms.

A cationic dicarbene complex of iron. The crystal structure of [Fe(CO)2(S2CNMe2)(CNMe2)2S]PF6 · C2H4Cl2

Abstract The structure of the compound [Fe(CO)2(S2CNMe2)(CNMe2)2S]PF6 · 1 2 C2H4Cl2 has been determined by X-ray crystallography. The compound crystallizes in space group C2/c with eight formula units in a unit cell of dimensions a 23.939(18), b 15.771(7), c 12.314(4) A, β 92.01(5)°. Full-matrix least-squares refinement of 2084 counter data yielded R = 0.051. The complex cation contains an unusual chelating dicarbene ligand, and the structure of this complex is compared with related species. The bonding properties of the dicarbene ligand are discussed.

Synthesis and reactions of xanthate and thioxanthate carbonyl complexes of molybdenum and tungsten

Abstract A series of complexes CpM(CO) n S 2 CX (M = Mo, W; n = 2, 3; X = OR, SR; R = Me, Et) has been prepared by the reaction of xanthates and thioxanthates with CpM(CO) 3 Cl. The dicarbonyl compounds are the exclusive products after sufficiently long reaction times and are produced at least partially through the tricarbonyl species as intermediates. The conversion of CpM(CO) 2 S 2 CX to CpM(CO) 2 S 3 CX is not a simple first-order process but is catalyzed by Cl − and/or S 2 CX − . The tricarbonyl species can be alkylated at the uncoordinated sulfur atom to give ionic di- or tri-thiocarbonate complexes.

THE CRYSTAL STRUCTURE OF DIMETHYLDITHIOCARBAMATO(TRIPHENYLPHOSPHINE)-TRICARBONYLMANGANESE(I)

Abstract The structure of (C6H5), PMn(CO)3S2CN(CH3)2, which is formed as a by-product in the synthesis of (C6H5)3PMn(CO)3CSN(CH3)2, has been determined by single-crystal X-ray diffraction techniques. The compound crystallizes in space group C2/c with 16 molecules in a unit cell of dimensions a=56.14 A; b=8.778 A; c=19.75 A; β=102.05°. Atomic positions were refined by full-matrix least-squares methods to a final R of 0.083 using 2756 independent reflections. The independent synthesis of this compound is also described.

Reactions of Thiocarbamoyl compounds with vaska complexes: mechanism and stereochemistry

Abstract Bis(dimethylthiocarbamoyl)sulfide, (Me 2 NCS) 2 S, reacts with (PH 3 P) 2 MCOCl complexes giving ionic species [Ph 3 PM(η 2 -CSNMe 2 )(S 2 CNMe 2 )CO]X (M = Rh, Ir; X = Cl, PF 6 ) as kinetic products. On standing solution, [Ph 3 PRh(η 2 -CSNMe 2 )(S 2 CNMe 2 )CO]Cl is slowly transformed into the thermodynamic product Ph 3 PRh(η 2 -CSNMe 2 )S 2 CNMe 2 )Cl. The known reactions of Vaska-type complexes with Me 2 NCSCl to give [ trans -(Ph 3 P) 2 Ir(η 2 -CSNMe 2 )COCl]Cl and trans -(Ph 3 P) 2 Rh(η 2 -CSNMe 2 )Cl 2 probably follow a similar course. (PH 3 P)RuNOCl reacts with (Me 2 NCS) 2 S and Me 2 NCSCl in the same way as (Ph 3 P) 2 IrCOCl, but reacts with (Me 2 NCS) 2 NPh to give [ trans -(Ph 3 P) 2 Ru(η 2 -CSNMe 2 )NOCl]PF 6 . The mechanism and stereochemistry of these reactions are discussed. Reactions were monitored by NMR spectroscopy in an attempt to identify intermediate η 1 -thiocarboxamido complexes, but no such species could be detected.