(1Z,3Z)-1,4-Diphenyl-1,4-bis(p-tolylmethylthio)-1,3-butadiene

Abstract

FREEMAN, LU, ZILLER AND RODRIGUEZ 659H atoms were included using a riding model with d(C--H) = 0.96/I, and Uiso = 0.08 A :. Structure solution and refinement used either our locally modified version of the UCLA Crystallographic Package or the SHELXTL-Plus88 program set . Acta Cryst. (1995). C51, 659-661 (IZ,3Z)-1,4-Diphenyl-1,4-bis(ptolylmethylthio)-l,3-butadieneWe thank the National Institutes of Health (grant AI 24779) and the National Science Foundation (grant CHE-90-15849) for support of this research. Funds for the purchase of the Siemens R3m/V diffractometer system were made available from the National Science Foundation under grant CHE-85-14495. Lists AbstractThe crystal structure of (1Z,3Z)-1,4-diphenyl-1,4-bis-(p-tolylmethylthio)-l,3-butadiene (1), C32H3052, is described. Compound (1) has an s-trans conformation. The single bond length, C(2)---C(2'), in compound (1) (1)is comparable to that in 1,3-butadiene (1.34A). The short C--C single and double bonds in (1) may be attributed to delocalization (resonance) over the planar four-atom unit, hybridization changes, the presence of the S atoms, and/or other factors. CommentThe addition of p-tolylmethanethiol to 1,4-diphenyl- Freeman, Lu, Zeng & Rodriguez, 1994), or (Z)-1,4-diphenyl-1-(p-tolylmethylthio)but-1-en-3-yne (Zschunke, Mugge, Hintzche & Schroth, 1992) depending on the solvent system and the ratio of reactants. The reaction of thiols with polyalkynes is of interest in the synthesis of 1,2-dithiacyclohexa-3,5-dienes (1,2-dithiins) in general and of the bioactive thiarubrines in particular ; Rodriguez, Aregullin, Nishida, Uehara, Wrangham, Abramowski, delocalization of rr electrons in 1,3-dienes are topics of considerable discussion and controversy (Bartell, 1978;Dewar & Gleicher, 1965;Fischer & Michl, 1987;Popov & Kogan, 1968; Marias, Sheppard & Stoicheff, 1962;Simmons, 1970;Wiberg, Rosenberg & Rablen, 1991). CH3(1)In compound (1) the conformation of the 1,3-butadiene moiety is trans-planar. The planes of the two phenyl rings attached to C(1) and C(I') are both tilted 39.7 ° from the 1,3-butadiene plane. The single bond length, C(2)--C(2'), of 1.432 (5)A in compound (1) is shorter than the C(3)--C(4) bond (1.48A) in 1,3-butadiene and the double-bond length, C(1)---C(2), of 1.350 (3)A is comparable to that in 1,3-butadiene (1.34 A). The short C---C single and double bonds in (1) may be attributed to delocalization (resonance) over the planar four-C-atom unit, hybridization changes, the presence of the S atoms, and/or other factors. 1.388 (5) C(12)--C(13) 1.386 (4) C(13)--C (14) 1.387 (4) C(13)--C(16) 1.513 (6) C(14)--C (15) 1.384 (5) C(I)--S(1)--C (9) 100.1 (1)The structure was solved using direct methods (SHELXTLPlus88; and the UCLA Crystallographic Package . H atoms were located and included with isotropic temperature factors.We thank the National Institutes of Health (AI 24779) and the National Scince Foundation (grant CHE-90-15849) for support of this research. Funds for the purchase of the Siemens R3m/V diffractometer system were made a...