Crystal Structures of the cis- and trans-Chlordanes and Their Photoisomers

Abstract

The crystal structures of the cis- and trans-chlordanes and their photoisomers, C₁₀H₆Cl₈, have been determined at 295(1) K by direct methods and refined by least squares. (1) cis-Chlordane: monoclinic P2₁/c, a 13.742(9), b 8.073(4), c 13.299(5) Å, β 93.81(4)º, Z 4. R 0.050 (1322 'observed' reflections). (2) trans-Chlordane: monoclinic, P2₁/a, a 15.762(5), b 7.694(2), c 12.526(4) Å, β 93.38(4)º, Z 4. R 0.052 (1678 'observed' reflections). (3) Photo-cis-chlordane: monoclinic, P 2₁/n, a 12.403(3), b 13.830(4), c 8.310(2) Å, β 96.75(2)º, Z 4. R 0.056 (1501 'observed' reflections). (4) Photo-trans-chlordane: monoclinic, P2₁/c,a 16.521(5), b 6.699(2), c 14.431(6)& 11 115.68(3)º, Z 4. R 0.047 (1302 'observed' reflections). An exceedingly long carbon-carbon bond (1.66(1) Å) is observed in (4).