The Application of Lanthanide Shift Reagent. I. Conformational Analysis of 1-[2-(1, 3-Dimethyl-2-butenylidene) hydrazino]-phthalazine (DJ-1461) by Lanthanide Induced Shifts

Abstract

The structure of DJ-1461 in solution was determined by using lanthanide shift reagents. The position of the lanthanide ion and the protons of DJ-1461 in the complex were determined using the McConnell-Robertson equation. The shifts induced by lanthanide shift reagents agreed well with the calculated values, on the assumption that their origin is of pseudocontact nature. The europium ion-N² bond length was as long as 3.2 Å (phthalazine N² is set at the origin of the right handed polar co-ordinates system). It was found that the side chain of the DJ-1461 has an anti form towards the C=N bond, and the two double bonds S-cis configuration.