Co[(C6H10)(NH3)2][C6H2(COO)4] • 2H2O and Zn[(C6H12)(NH3)2][C6H2(COO)4] • 1/2H2O -: Two zeolite-like three-dimensional coordination polymers

Monoclinic single crystals of Co[(C6H10)(NH3)(2)]-[C6H2(COO)(4)].2H(2)O have been prepared in aqueous solution at 80 degreesC. Space group C2/c (no. 15), a = 1065.92(8), b = 1568.97(9), c = 1140.88(9) pm, beta = 90.101(6)degrees, V = 1.9080(2) nm(3), Z = 4. Co2+, which is situated on a twofold crystallographic axis, is coordinated in a moderately distorted tetrahedral fashion by four oxygen atoms stemming from the pyromellitate anions (Co-O 197.87(12) and 200.64(12) pm). A three-dimensionally connected coordination polymer is made up by Co2+ and C6H2(COO)(4)(4-) featuring channel-like voids, which accomodate water molecules and (C6H10)(NH3)(2)(2+) cations compensating for the negative excess charge of the three-dimensional framework. Thermogravimetric analysis in air showed that the dehydrated compound was stable between 198 and 361 degreesC. Further decomposition yielded CoO. Zn[(C6H12)(NH3)(2)][C6H2(COO)(4)].1/2H(2)O (2) was prepared analogously to 1 employing 1,6-diaminohexane. Space group P2(1)/n (no. 14), a =1087.78(8), b = 1515.18(11), c = 1162.21(10) pm, beta = 96.249(7)degrees, V = 1.9042(3) nm(3), Z = 4. Zn2+ is coordinated tetrahedrally like Co2+ by oxygen atoms of the pyromellitate anions (Zn-O 195.0(4) - 197.8(4)). The connection of Zn2+ with the anions leads similar to I to a three-dimensional framework with voids accomodating (C6H12)(NH3)(2)(2+) -cations and water molecules. 2 was stable anhydrously between approx. 120 and 340 degreesC, the further decomposition was completed at 700 degreesC yielding ZnO.