Pyrazole-4-sulfonate networks of alkali and alkaline-earth metals.Effect of cation size,charge,H-bonding and aromatic interactions on the three-dimensional supramolecular architecture

摘要

Variation of cation size and/or charge produces profound structural changes in the networks formed by pyrazole-4-sulfonate(L)with alkali and alkaline-earth metal cations.The zwitterionic ligand(HL)itself forms a robust three-dimensional H-bonded network:tetragonal P4_2/mbc,a=10.863(1)A,c=9.195(1)A,V=1085.0(2)A~3,Z=8.The Na,K,Ca and Ba salts described herein are the first structurally characterized networks formed by L.NaL(H_2O)_2,orthorhombic Pbca,a=9.979(3)A,b=7.848(3)A,c=20.583(7)A,V=1612.0(9)A,Z=8;KL(H_2O),orthorhombic Pbca,a=8.174(1)A,b=8.972(1)A,c=19.912(3)A,V=1460.4(4)A,Z=8;CaL(H_2O)_3,triclinic P1,a=5.9972(6)A,b=9.2102(9)A,c=12.957(1)A,alpha=76.536(1)deg,beta=89.264(2)deg,gamma=79.057(2)deg,V=683.0(1)A,Z=2;BaL(H_2O).H_2O,monoclinic P2_1/c.a=11.386(1)A,b=4.9098(6)A,c=24.348(3)A,beta=90.702(2)deg,V=1361.0(3)A,Z=4.All four metal sulfonate networks have an alternating inorganic-organic layered structure,reinforced by multiple H-bonding within the inorganic layer as well as between the organic and inorganic layers;extended pi-pi stacking and edge-to-face aromatic interactions within the organic layer provide further lattice strength.