Inducing polarity in [VO3]nn- chain compounds using asymmetric hydrogen-bonding networks
Abstract
1,4-Bis(3-aminopropyl)piperazine, (R)-3-aminopiperidine and (S)-3-aminopiperidine were used in the syntheses of [C10H26N4][VO3](2)center dot 2H(2)O, [(R)-C5H14N2][VO3](2) and [(S)-C5H14N2][VO3](2), which all contain similar [VO3](n)(n-) chains. Inversion symmetry within the 1,4-bis(3-aminopropyl)piperazine allows for crystallization of [C10H26N4][VO3](2)center dot 2H(2)O in a centrosymmetric space group, while the use of enantiomerically pure sources of either (R)-3-aminopiperidine or (S)-3-aminopiperidine forces crystallographic noncentrosymmetry. Moreover, asymmetry in the hydrogen-bonding networks between the metavanadate chains and either [(R)-3-aminopiperidineH(2)](2+) or [(S)-3-aminopiperidineH(2)](2+) cations directs alignment of the chains and crystallization in a polar space group (C2, no. 5). Component and net dipole moments were calculated using iterative-Hirshfeld partial atomic charges. [(R)-C5H14N2][VO3](2) and [(S)-C5H14N2][VO3](2) both display type 1 phase-matching capabilities and exhibit second harmonic generation activities of similar to 140 x alpha-SiO2. (C) 2012 Elsevier Inc. All rights reserved. --author-supplied description