Crystal structures of two different multi-component crystals consisting of 1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline and fumaric acid

Abstract

Two different multi-component crystals consisting of papaverine [1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline, C20H21NO4] and fumaric acid [C4H4O4] were obtained. Single-crystal X-ray structure analysis revealed that one, C20H21NO4·1.5C4H4O4 (I), is a salt co-crystal composed of salt-forming and non-salt-forming molecules, and the other, C20H21NO4·0.5C4H4O4 (II), is a salt–co-crystal intermediate (i.e., in an intermediate state between a salt and a co-crystal). In this study, one state (crystal structure at 100 K) within the salt–co-crystal continuum is defined as the ‘intermediate’.

Keywords

• crystal structure
• fumaric acid
• papaverine
• multi-component crystal