Two new tetramethylammonium zinc phosphates: N(CH3)(4)center dot Zn(HPO4)(H2PO4), an open framework phase built up from a low-density 12-ring topology, and N(CH3)(4)center dot Zn(H2PO4)(3), a molecular cluster

The solution-phase syntheses and X-ray single crystal structures of N(CH3)(4) . Zn(HPO4)(H2PO4) and N(CH3)(4) . Zn(H2PO4)(3), two new tetramethylammonium (TMA) zinc phosphates, are described, N(CH3)(4) . Zn(HPO4)(H2PO4) is a three-dimensional framework phase built up from ZnO4, HPO4, and H2PO4 tetrahedra sharing vertices, The polyhedral connectivity results in a novel, low-density framework topology, based on tetrahedral 12-rings. TMA cations provide extraframework charge balancing, and occupy the 12-ring channel network. N(CH3)(4) . Zn(H2PO4)(3) is a ''zero-dimensional'' (molecular) phase built up from the same polyhedral units, formed into discrete anionic clusters, Crystal data: N(CH3)(4) . Zn(HPO4)(H2PO4), M-r = 332.49, monoclinic, space group Pc (No. 7), a = 8.443 (2) Angstrom, b = 13.779 (4) Angstrom, c = 10.170 (2) Angstrom, beta = 91.91 (2)degrees, V = 1182.9 (5) Angstrom(3) Z = 4, R(F) = 4.69%) R-w(F) = 5.46% [3284 observed reflections with I > 3 sigma(1)]. N(CH3)(4) . Zn(HPO4)(H2PO4)(3), M-r = 430.49, triclinic, space group P (1) over bar (No. 2), a = 8.950 (2) Angstrom, b = 10.068 (2) Angstrom, c = 10.263 (2) Angstrom, alpha = 61.649 (9)degrees, beta = 76.04 (2)degrees, gamma = 76.72 (1)degrees, V = 782.5 (2) Angstrom(3), Z = 2, R(F) = 4.22%, R-w(F) = 4.77% [3038 observed reflections with I>3 sigma(I)]. (C) 1977 Academic Press.