S0329

STRUCTURES OF TWO 6-SUBSTITUTED [(I) CYCLO HEXYL & (II) 4-CHLOROPHENOXY]2,10-DICHLORO-12H-DIBENZO [d,g] [1,3,2] DIOXAPHOSPHOCIN 6-OXIDES-CONFORMATION OF 8-MEMBERED HETEROCYCLIC RING. M. Krishnaiah, C. Devendranath Reddy, Departments of Physics & Chemistry, Sri Venkateswara University, Tirupati-517 502, India

Organophosphorus heterocycles containing phosphoryl unit reacts rapidly with proteins and nucleic acids in the cell to alicylate carboxyl suithydroxyl and amino groups. These molecules are often important in terms of multiple applications as insecticides, bactericides, fungicides and lubricants etc. A few members of this family were evaluated for toxicity in the insect P americana (C. D. Reddy et al., 1991).

Structure analysis of the title compounds has been carried out as part of a series on 8-membered dioxaphosphocin derivatives to understand the effect of the substituents on the molecular geometry and conformation of hetero ring. Both compounds are crystallized from 1-butanol.

Crystal data: (I):C₁₉H₁₉PO₃CI₂,monoclinic, P2₁/c with a= 11.394 (1) b=24.254(2), c=13.576(1)Å, [[beta]]=91.94(1)deg., v=3749.6(5)Å³, z=8, [[rho]]_c=1.407,[[rho]]_o=1.40Mg/cm^3,u(cuK[[alpha]]) =41.23cm^-1, F(000) =1648. R=0.058 and Rw=0.073 for 5687 significant reflections [I>=3[[sigma]](I)]. (II)C₁₉H₁₂PO₄CI₃, Mr=441.634, triclinic, P-1 with a=11.392(1), b=15.936(1),c=10.617(1)Å, [[alpha]] = 93.14(1), [[beta]] = 101.10(1), [[gamma]] = 86.27 (1)deg., v=1885.6(3)Å³,z=4,[[rho]]_c= 1.556,[[rho]]_o= 1.550Mg/cm³, u(CuK[[alpha]]) =55.24cm^-1, F(000)=896. R=0.0895 and Rw=0.1108 for 5574 significant reflections [1 >=3[[sigma]](1)].

Both structures were solved by direct methods and refined by full matrix least-squares method using SHELX-76. The dioxaphosphocin ring shows a boat-chair conformation in both structures. The chair form of cyclohexane moieties of both molecules are oriented at 75.8 and 47.6deg. in the former, where as the phenyl rings are oriented at 22.6 and 46.6deg. with their hetero planes of the asymmetric unit.