Tetrachloro tetrahalo

Chromium, tetraaquadichloro-chloride dihydrate hydrate isomerism, 1, 183 Chromium, tetrabromo-solvated, 3, 758 synthesis, 3, 763 Chromium, tetrachloro-antiferromagnetic, 3, 761 ferromagnetic magnetic properties, 3,7559 optical properties, 3,759 structure, 3,759 solvated, 3. 758 synthesis. 3, 759 Chromium, tetrachlorooxy-tetraphenylarsenate stereochemistry, 1,44 Chromium, tetrahalo-, 3,889 Chromium, tetrakis(dioxygen)-stereochemistry, 1,94 Chromium, triamminediperoxy-structure. 1, 78 Chromium, tricyanodiperoxy-structure, 1, 78 Chromium, trifluoro-electronic spectra, 3, 757 magnetic properties, 3, 757 structures, 3, 757 synthesis, 3, 756 Chromium, trihalo-clcctronic spectra, 3, 764 magnetic properties, 3, 764 structure, 3, 764 synthesis, 3, 764 Chromium, tris(acetylacetone)-structure. 1, 65 Chromium, tris(bipyridyl)-... 

X = Cl) was subsequently carboxylated in the 3-position. In the presence of a proton donor, the major product from reduction of 89 (X = F) was the symmetrical tetrahalo 91. When pentachloropyridine (89, X = Cl) was reduced without an added proton donor, the tetrachloro 91 (X = Cl) was the major product dimerization to bipyridyl (90, X = Cl) was sterically inhibited. 

The disulfone 546, l,3-dithietane-l,l,3,3-tetroxide, was believed to be non-planar according to its dipole moment but the x-ray analysis indicates a planar structure. Its IR spectrum has been analyzed and a phase transition has been detected. X-ray analyses of l,3-dithietane-2,2,4,4-tetrahalo(F, Cl, Br)-1,1,3,3-tetroxides and 1,3-dithietane-2,2,4,4-tetrachloro-l,1-dioxide indicate planar and nearly square structures. The planar structure of the latter mono-sulfone contrasts with the puckered structure of the monosulfoxide 544. 

The thermal and photochemical [4 + 2] cycloadditions of o-quinones with olefinic and acetylenic dienophiles have been extensively reviewed4,5,200 and include their 4tt heterodiene Diels-Alder reactions with olefins,201-204 vinyl ethers,205 enamines,206 selected dienes,207-209 dipheny-lketenimines,210 ketenes,209,210 fulvenes,211 and selected heterocycles including furan,207-209,212 benzofuran,209,212,215 indoles,213 azepines,214 and 1,2-diazepines.214 The tetrahalo-substituted o-quinones, tetrachloro- and tetrabromo-o-quinone, generally participate in heterodiene [4 + 2] cycloadditions at an increased rate over the unsubstituted systems and generally provide higher overall yields of the Diels-Alder products.4,5 With simple olefins, the dienophile geometry is maintained in the course of the thermal [4 4- 2] cycloadditions [Eq. (52)],203,204... 

Chromates, heptafluoro-, 927 Chromates, hexacyano-, 703, 773 production, 704 Chromates, hexafluoro-, 927 Chromates, hexahalo-, 889 Chromates, hexaiodo-, 766 Chromates, oxohalo-, 935 Chromates, pentafluoro-, 927 Chromates, pentahalo-, 766 Chromates, tetrabromo-solvated, 758 synthesis, 763 Chromates, tetrachloro-antiferromagnetic, 761 ferromagnetic magnetic properties, 759 optical properties, 759 structure, 759 solvated, 758 synthesis, 759 Chromates, tetrahalo-, 889 Chromates, trifluoro-electronic spectra, 757 magnetic properties, 757 structures, 757 synthesis, 756 Chromates, trihalo-electronic spectra, 764 magnetic properties, 764 structure, 764 synthesis, 764 Chromium... 

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