structure structure (organic substances) K 9000 17 -030 X-Ray Crystallographic Study of α-Brominated Diketo Tetraquinanes (I)-(IV). Conformational Effects of the Number of Halogens and Their Position on Bond Length and Solid-State Conformation. --(PAQUETTE, L. A.; BRANAN, B. M.; ROGERS, R. D.; Tetrahedron 48 (1992) 2, 297-306; Dep. Chem., Ohio State Univ., Columbus, OH 43210, USA; EN)