The structure of 5-norbornene-2,3-endo-dicarboxylic anhydride

Abstract

Acta Cryst. (1969). B25, 2465The Structure of 5-Norbornene-2,3-endo-diearboxylie Anhydride BY RICCARDO DESTRO, GIUSEPPE FILIPPINI, CARLO MARIA GRAMACCIOLI AND MASSIMO SIMONETTA Istituto di Chimica Fisica, Universitdt di Milano, Milano, Italy (Received 3 February 1969)The crystal and molecular structure of 5-norbornene-2,3-endo-dicarboxylic anhydride* has been determined and refined by least-squares methods. The crystals are orthorhombic, space group P2~212j, with a= 13"539, b=9"565, c=5"972/~ and four molecules per unit cell. Intensity data were collected visually from Weissenberg photographs about two crystal axes. The final R index is 0.071 ; the average standard deviation in the atomic positions is about 0.004 A,. The anisotropic temperature factors of the heavier atoms in the molecule can be accounted for by a Schomaker-Trueblood rigid-body treatment; on this basis, corrections to the observed bond distances are in the range 0"007-0.010/~. In the norbornene nucleus, the bridgehead angle C(1)-C(7)-C(4) is 93.5 °. The geometry of the anhydride group is closely similar to that found in succinic anhydride. The two C-C single bonds which connect the anhydride ring with the cyclopentene ring are found to be significantly longer (1.57 and 1.58/~) than normal. A similar feature observed in cyclopentadiene dimer probably accounts for its chemical reactivity in the Cope rearrangement.

Diels–Alder adducts of maleic anhydride and dienes: new compounds by crystallization

“…The plane formed by the methylene bridge (C3/C7/C6) encloses a dihedral angle of 128.5 (1) with plane 1 and 118.4 (1) with plane 2 of the norbornene skeleton. These results agree well with the crystal structure of (I) determined at room temperature using Weissenberg photographs (Destro et al, 1969).…”

Chemistry of proximal π-bond systems. Part IV. The structure of 5,6-dimethylenebicyclo[2,2,1]hept-2-ene molybdenum tricarbonyl

“…Tables of observed and calculated structure factors are available from the Depository of Unpublished Data.' ~o s t bond lengths and angles in the hydrocarbon moiety agree well with values found for various uncomplexed bicyclo[2,2,l]hept-2-ene derivatives (11)(12)(13)(14). Bond lengths are not significantly different (G3a) from standard values (15) and like the other X-ray structure determinations of such molecules (1 1-14), the bonds C(1)-C(7) (1.53 l(5) A) and C(4)-C(7) (1.531 (5) Csp3-Csp2, average = 1.522(6) A do not differ significantly from these values.…”

Crystal and molecular structure of bicyclo[2,2,1]hept-5-ene-2,3-endo-dicarboxylic acid

“…X-ray structures of two similar compounds have been reported; the endo anhydride of the diacid reported here (Destro et aL, 1969) and the anhydride of (5) 107-3 108.1 104-4 C(2)--C(1)--C (7) 99-9 98.4 100-8 C(3)--C(4)--C (7) 98-9 97-8 101.0 C(6)--C(1)--C (7) 100-7 101.3 100.6 C(5)--C(4)--C (7) 100-8 101.1 99.4…”

“…t (Destro et aL, 1969): bicyclo[2,2,1]hept-5-ene-2,3-endo-dicarboxylic anhydride. The numbering system has been altered to agree with that of the other two structures.…”