Two Interpenetrating 3D Networks Which Generate Spacious Sealed-Off Compartments Enclosing of the Order of 20 Solvent Molecules in the Structures of Zn(CN)(NO3)(tpt)2/3.cntdot.solv (tpt = 2,4,6-tri(4-pyridyl)-1,3,5-triazine, solv = .apprx.3/4C2H2Cl4.cntdot.3/4CH3OH or .apprx.3/2CHCl3.cntdot.1/3CH3OH)