The 1H and 15N NMR spectra of several 15N-labeled pyridoxal-5'-phosphate model systems have been measured at low temperature in various aprotic and protic solvents of different polarity, i.e., dichloromethane-d2, acetonitrile-d3, tetrahydrofuran-d8, freon mixture CDF3/CDClF2, and methanol. In particular, the 15N-labeled 5'-triisopropyl-silyl ether of N-(pyridoxylidene)-tolylamine (1a), N-(pyrid...

A structure-based approach to the mechanism of ion pumping in bacteriorhodopsin (BR) has fostered new hypotheses for the detailed molecular changes that underlie ion transport in this light-driven pump. Isomerization of the retinal from all-trans to 13-cis in response to absorption of the energy of a photon is thought to lead to proton transfer from the initially protonated Schiff base to an an...

The title complex, [Fe(C(12)H(9)ClNO(2))(3)], is a mononuclear Schiff base iron(III) compound. The Fe atom is six-coordinated by three phenolic O and three imine N atoms from three Schiff base ligands in an octa-hedral geometry.

An octahedral ruthenium(II) Schiff base complexes of the type [Ru(CO)(Py)L] (L = dianion of the Schiff bases derived from acetoacetanilide with o-phenylenediamine and salicylaldehyde/ohydroxyacetophenone/o-vanillin/2-hydroxy-1-naphthaldehyde) have been synthesized from the reactions of equimolar ratio of [Ru(CO)(PPh3)2(Py)] and Schiff bases in benzene. The formation of the Schiff base ligands a...

The ligand N-(2-hydr-oxy-3-methoxy-benzyl-idene)glycylglycine (H(3)L), a Schiff base derived from glycylglycine and 3-methoxy-salicylaldehyde, was used in the synthesis of a new organic-inorganic coordination complex, [Mn(H(2)O)(6)][Cu(C(12)H(11)N(2)O(5))](2)·6H(2)O. The Mn(II) atom is located on an inversion center and is coordinated to six water mol-ecules in a slightly distorted octa-hedral ...

The Bürgi-Dunitz angle (αBD) describes the trajectory of approach of a nucleophile to an electrophile. The adoption of a stereoelectronically favorable αBD can necessitate significant reactive-group repositioning over the course of bond formation. In the context of enzyme catalysis, interactions with the protein constrain substrate rotation, which could necessitate structural transformations du...