Molecular Structure of 3,4-Difluorofuran-2,5-dione (Difluoromaleic Anhydride) As Determined by Electron Diffraction and Microwave Spectroscopy in the Gas Phase and by Theoretical Computations
作者:Basil T. Abdo、Halima Amer、R. Eric Banks、Paul T. Brain、A. Peter Cox、Oliver J. Dunning、Vincent Murtagh、David W. H. Rankin、Heather E. Robertson、Bruce A. Smart
DOI:10.1021/jp984554o
日期:1999.3.25
The structure of 3,4-difluorofuran-2,5-dione has been determined experimentally in the gas phase by microwave spectroscopy using rotation constants derived from five isotopomers and by a combined analysis of electron-diffraction and microwave data. The geometry is planar with C-2v symmetry. Structural parameters [distances (r(alpha)degrees)/pm, angles angle(alpha)/deg, (1 sigma errors)] for the combined analysis are: r(C=O) = 119.0(1); r(C-F) = 130.9(2); r-(C=C) = 133.2(3), r(O-C) = 139.3(1); r(C-C) = 148.5(2); angle C-C=C = 108.3(1); angle C=C-F = 129.9(1); angle C-C=O = 129.3(1); angle C-O-C = 108.9(1); angle O-C-C = 107.2(1). These values are in excellent agreement with those obtained in an ab initio study of the molecular geometry at the MP2/6-311+G*(2df) level of theory. The dipole moment of difluoromaleic anhydride has been determined experimentally by Stark-effect measurements to be 1.867(3) D.
Mono- and Difluorobutenedioic Acids
作者:Maynard S. Raasch、Ralph E. Miegel、John E. Castle
Dihydropyridazinones, pyridazinones and related compounds as fungicides
申请人:Rohm and Haas Company
公开号:US05631254A1
公开(公告)日:1997-05-20
This invention relates to substituted dihydropyridazinones, pyridazinones and related compounds, of the formula ##STR1## wherein A, Q, D and R1 are as defined within, compositions containing these compounds and methods of controlling agricultural and mammalian fungal diseases.