Etudes structurales en relation avec le concept de substitution "capto-dative". I. Structures aux rayons X du bis(ethylthio)-2,3 diphényl-2,3 butanedinitrile-1,1 et du bis(éthylthio)-2,3 bis(p-tolyl)-2,3 butanedinitrile-1,4

The crystal structures of the title compounds have been determined using X-Ray diffractometry in order to study the effects of capto-dative substitution on molecular geometry. The carbon-carbon central bond is significantly stretched. 2, 3-Bis (ethylthio) -2, 3-diphenyl-1, 4-butanedinitrile (compound A) is triclinic, P1, with a = 15.703 (9), b = 14. 902(5), c = 8.655(4)A, δ = 97.52(3), β = 89.87(4)°, γ = 75.59(4)°, V = 1943.3 A3, Z = 4 and Dx = 1.20 Mg m−3. 2, 3-Bis (ethylthio)-2, 3-bis (p-tolyl)-1, 4-butanedinitrile (compound B) is monoclinic, P2/n with a = 16-872(8), b = 12, O82(5), c = 10.329(5)A, β = 94.16(4)°, V = 2100.0 A3, Z = 4 and Dx = 1.21 Mg m−3.