Crystal structures of two different multi-component crystals consisting of 1-(3,4-di-meth-oxy-benz-yl)-6,7-di-meth-oxy-iso-quinoline and fumaric acid.

Two different multi-component crystals consisting of papaverine [1-(3,4-di-meth-oxy-benz-yl)-6,7-di-meth-oxy-iso-quinoline, CHNO] and fumaric acid [CHO] were obtained. Single-crystal X-ray structure analysis revealed that one, CHNO·1.5CHO (I), is a salt co-crystal composed of salt-forming and non-salt-forming mol-ecules, and the other, CHNO·0.5CHO (II), is a salt-co-crystal inter-mediate (, in an inter-mediate 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 'inter-mediate'.