1,2-Bis(dimethylarsino)benzene

changed changed 477203033 Diars.png correct ?? Stereo, Kekulé, skeletal formula of 1,2-bis(dimethylarsino)benzene with some implicit hydrogens shown Diars-3D-balls-A.png correct ?? Ball and stick model of 1,2-bis(dimethylarsino)benzene (1,2-Phenylene)bis(dimethylarsane) DAS, Diars correct CAS 13246-32-7 correct FDA K3C0GW5M57 83261 75125 correct chemspider 236-227-9 2-Phenylene-bis-dimethylarsine 30628 correct EBI 2937031 3780 C[As](C)c1ccccc1[As](C)C C[As](C)C1=CC=CC=C1[As](C)C 1S/C10H16As2/c1-11(2)9-7-5-6-8-10(9)12(3)4/h5-8H,1-4H3 correct chemspider 1/C10H16As2/c1-11(2)9-7-5-6-8-10(9)12(3)4/h5-8H,1-4H3 HUBWRAMPQVYBRS-UHFFFAOYSA-N correct chemspider HUBWRAMPQVYBRS-UHFFFAOYAM C 10 As 2 H 16 286.0772 g mol−1 Colourless liquid 1.3992 g cm−3 97 to 101 at 150 Pa Toxic 1,2-Bis(dimethylarsino)benzene (diars) is the organoarsenic compound with the formula C6H4(As(CH3)2)2. The molecule consists of two dimethylarsino groups attached to adjacent carbon centers of a benzene ring. It is a chelating ligand in coordination chemistry. This colourless oil is commonly abbreviated "diars."Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. 0-12-352651-5. Coordination chemistry Related, but non-chelating organoarsenic ligands include triphenylarsine and trimethylarsine. Work on diars preceded the development of the chelating diphosphine ligands such as dppe, which are now prevalent in homogeneous catalysis. Diars is a bidentate ligand used in coordination chemistry. It was first described in 1939,Chatt, J.; Mann, F. G. "The Synthesis of Ditertiary Arsines. Meso- and Racemic Forms of Bis-4-Covalent-Arsenic Compounds" Journal of the Chemical Society, 1939, 610–615. 10.1039/JR9390000610 but it was popularized by R. S. Nyholm for its ability to stabilize metal complexes with unusual oxidation states and coordination numbers, e.g. TiCl4(diars)2. High coordination numbers arise because diars is fairly compact and the As-M bonds are long, which relieves crowding at the metal center. In terms of stabilizing unusual oxidation states, diars stabilizes Ni(III), as in [NiCl2(diars)2]Cl. Of historical interest is the supposedly diamagnetic [Ni(diars)3](ClO4)2, obtained by heating nickel perchlorate with diars. Octahedral d8 complexes characteristically have triplet ground states, so the diamagnetism of this complex was puzzling. Later by X-ray crystallography, the complex was shown to be pentacoordinate with the formula [Ni(triars)(diars)](ClO4)2, where triars is the tridentate ligand [C6H4As(CH3)2]2As(CH3), arising from the elimination of trimethylarsine.B. Bosnich, R. S. Nyholm, P. J. Pauling, M. L. Tobe "A nickel(II)-catalyzed synthesis of a triarsine from a diarsine" J. Am. Chem. Soc. 1968, volume 90, pp 4741–4742. 10.1021/ja01019a049Anthony Nicholl Rail; Some new reactions of a ditertiary arsine ligand; Ph.D. Thesis; University College London; 1973 Preparation and handling Diars is prepared by the reaction of ortho-dichlorobenzene and sodium dimethylarsenide:Feltham, R. D.; Silverthorn, W. "o-Phenylenebis(dimethylarsine)" Inorganic Syntheses 1967, Vol. X, pp. 159–164. 10.1002/9780470132418.ch24 C6H4Cl2 + 2 NaAs(CH3)2 → C6H4(As(CH3)2)2 + 2 NaCl It is a colorless liquid. Oxygen converts diars to the dioxide, C6H4(As(CH3)2O)2. References Category:ortho-Phenylene compounds Category:Chelating agents Category:Cacodyl compounds