In the title compound, C(11)H(10)N(2)O(5), the amide group is nearly coplanar and the ester group approximately perpendicular to the vinyl C-HC=CH-C group [dihedral angles of 5.0 (2) and 88.89 (5)°, respectively]. This results in a short intra-molecular O =C⋯O=C contact of 2.7201 (17) Å between the amide O atom and the ester carbonyl C atom. The prop-2-enamide fragment and the nitro group make ...

In the title compound, [Sn(C(5)H(9)O(2))(2)(C(3)S(5))], the immediate environment around the Sn centre is defined by two S and two C atoms that define an approximately tetra-hedral geometry. The close approach of the pendant carbonyl O atoms [Sn-O = 2.577 (3) and 2.573 (3) Å] increases the coordination number to six. Supra-molecular chains are formed along the a axis in the crystal structure ow...

Carbonyl-carbonyl interactions between adjacent backbone amides have been implicated in the conformational stability of proteins. By combining experimental and computational approaches, we show that relevant amidic carbonyl groups associate through an n→π* donor-acceptor interaction with an energy of at least 0.27 kcal/mol. The n→π* interaction between two thioamides is 3-fold stronger than bet...

The asymmetric unit of the title compound, C(26)H(36)N(2)O(8), comprises two independent mol-ecules. In each mol-ecule, the two pyrrole rings are linked by a -CH(2)CH(2)- bridge, with dihedral angles between the two pyrrole rings of 14.5 (3) and 16.4 (3)° in the two mol-ecules. Each pyrrole ring carries 2- and 5-methyl substituents and eth-oxy-carbonyl groups at the 3- and 5-positions.

Raman spectroscopy is applied for the first time to elucidate the different conformations of the carrier transport molecule, valinomycin. Splitting of the ester and amide carbonyl stretch vibrations is observed in the Raman spectrum of crystals of valinomycin grown from both n-octane and acetone. These observations support the contention that some ester carbonyl groups are intramolecularly hydr...

Octahedral, trigonal prismatic, and capped square pyramidal structures have been optimized for the Ru(6)C(CO)(n) clusters (15 ≤ n ≤ 20) using density functional theory. The experimentally known very stable Ru(6)C(CO)(17) is predicted to have an octahedral structure in accord with experiment as well as the Wade-Mingos rules. The stability of Ru(6)C(CO)(17) is indicated by its high carbonyl disso...

In the title compound, C(17)H(19)NO(5), the cyclo-hexene ring is in a half-chair conformation and the isoxazole ring in an envelope conformation with the N atom as the flap. The C atoms in the 4- and 6-positions are of the same absolute configuration, whereas the C atom in the 5-position is of the opposite configuration, i.e. (4S*,5R*,6S*). The methyl fragment of the eth-oxy-carbonyl group at p...

It is demonstrated that J connectivity between amide protons and hydrogen-bond-accepting carbonyl carbons can be observed in perdeuterated human ubiquitin. A selective pulse scheme is used to detect these small 2hJHC' interactions in the presence of the much larger through-covalent-bond 2JHC' and 3JHC' couplings. The ratio of the observed through-H-bond correlation intensity and the 2JHC' conne...