Crystal Structure of the (1:1) Addition Compound Cyclohexane-1,4-dione--Diiodoacetylene.

Crystal and Molecular Structure of 3-Iodo-2-propynyl-N-butylcarbamate

“…The inter molecular I -O distance, 2.933(4) A , is consider ably shorter than the sum of the van-der-Waals radii of oxygen and iodine (3.5 A [7]). These contacts are identical with those reported for [cyclohexane-1,4-dione-I-C=C-I] (2.94 A [6]) and are longer than in the 1,4-dioxane-diidoacetylene adduct (2.65 A [5]), which is in accord with the stronger basic properties of 1,4-dioxane compared to cyclohexane-1,4-dione.…”

“…However, there are only two reports on adducts of Lewis acidic carbonhalide derivatives with oxygen atoms as Lewis base, viz. [l,4-dioxane-I-C=C-I] and [cyclohexane-1,4-dione-I-CEEC-I] [5,6],…”

Crystal Structures of Palladium(II) Ternary Complexes of 5-X-2-Aminobenzoic Acid with 1,10-Phenanthroline and Their Interaction with Calf Thymus DNA (Where X=Cl, Br and I)

“…Another shorter I · · · OϭC distance (2.94 Å) has also been observed for the crystal structure of the 1 : 1 diiodoacetylene-cyclohexane-1,4-dione adduct. 19) Cody and Murray-Rust 20) reported an extensive survey of the Cambridge Crystallographic Data Base for compounds containing C-I bonds that have C-I · · · O(N, S) distances less than 3.55 Å. They found the contacts between I and the nucleophiles are such that the distances are shortest with the C-I · · · O(N, S) angles close to 180°.…”

The crystal and molecular structure of trans-2,5-di-p-bromobenzyl-2,5-diethoxycarbonylcyclohexane 1,4-dione

“…The deviation from 180 ° is consistent with the considerable dipole moment of 1.3 D observed in solution (Hassel & Naeshagen, 1930;Lef6vre & Lef6vre, 1935). The corresponding angle in the 1:1 addition compound cyclohexane-l,4-dione/ diiodoacetylene is 155.6 ° (Groth & Hassel, 1965), and this is extended to 176 ° (Groth & Hassel, 1964b) in the cyclohexane-l,4-dione/mercuric chloride adduct. In cyclohexane-l,4-dioxime the angle between the two C= N directions is 129 ° (Groth, 1968).…”

“…In a critical review (Allinger & Wertz, 1973) of the dione conformation it was concluded that all available experimental data point to the existence of the twist-boat form in the gas, liquid, and solid phases. This conformation also persists in two 1:1 addition compounds of the dione with mercuric chloride (Groth & Hassel, 1964b) and with diiodoacetylene (Groth & Hassel, 1965) which were prepared and subjected to crystal-structure analysis. From n.m.r, evidence it has been suggested that 1,4-dimethylenecyclohexane also exists in the twist-boat form (Lambert, 1967;Lautenschlaeger & Wright, 1963).…”