Synthesis and crystal structure of guanidinium <scp>L</scp>-monohydrogentartrate: encapsulation of an optically nonlinear octupolar cation

Abstract

Encapsulation of an optically nonlinear octupolar guanidinium cation in a host polyanionic L-monohydrogentartrate lattice leads to a noncentrosymmetric orthorhombic P2 1 2 1 2 1 guest-host crystalline structure with cell parameters a=11.347 (2), b=11.162 (2), c=6.668 (2) A with Z=4. Final R=0.049 from 1229 independent reflections. The packing shows strong interlocking between the anionic and cationic sublattices by a multidirectional hydrogen-bonding network. The optimally oriented octupolar crystalline structure for the 222 crystal point group is defined and the corresponding reference maximal nonlinear susceptibility is compared to that of the present guanidinium crystal structure thus pointing out possible improvements via appropriate structural modifications