Kelley Annette, Akkina Subhash, Devarapally Goutham K, Nalla Soujanya, Pasam Divya, Madhabushi Shravani, Bond Marcus R
Department of Chemistry, Southeast Missouri State University, Cape Girardeau, MO 63701, USA.
Acta Crystallogr C. 2011 Jan;67(Pt 1):m22-34. doi: 10.1107/S0108270110049024. Epub 2010 Dec 18.
The structures of seven A(2)Cu(4)X(10) compounds containing quasi-planar oligomers are reported: bis(1,2,4-trimethylpyridinium) hexa-μ-chlorido-tetrachloridotetracuprate(II), (C(8)H(12)N)(2)[Cu(4)Cl(10)], (I), and the hexa-μ-bromido-tetrabromidotetracuprate(II) salts of 1,2,4-trimethylpyridinium, (C(8)H(12)N)(2)[Cu(4)Br(10)], (II), 3,4-dimethylpyridinium, (C(7)H(10)N)(2)[Cu(4)Br(10)], (III), 2,3-dimethylpyridinium, (C(7)H(10)N)(2)[Cu(4)Br(10)], (IV), 1-methylpyridinium, (C(6)H(8)N)(2)[Cu(4)Br(10)], (V), trimethylphenylammonium, (C(9)H(14)N)(2)[Cu(4)Br(10)], (VI), and 2,4-dimethylpyridinium, (C(7)H(10)N)(2)[Cu(4)Br(10)], (VII). The first four are isomorphous and contain stacks of tetracopper oligomers aggregated through semicoordinate Cu···X bond formation in a 4(5/2,1/2) stacking pattern. The 1-methylpyridinium salt also contains oligomers stacked in a 4(5/2,1/2) pattern, but is isomorphous with the known chloride analog instead. The trimethylphenylammonium salt contains stacks of oligomers arranged in a 4(3/2,1/2) stacking pattern similar to the tetramethylphosphonium analog. These six structures feature inversion-related organic cation pairs and hybrid oligomer/organic cation layers derived from the parent CuX(2) structure. The 2,4-dimethylpyridinium salt is isomorphous with the known (2-amino-4-methylpyridinium)(2)Cu(4)Cl(10) structure, in which isolated stacks of organic cations and of oligomers in a 4(1/2,1/2) pattern are found. In bis(3-chloro-1-methylpyridinium) octa-μ-bromido-tetrabromidopentacuprate(II), (C(6)H(7)ClN)[Cu(5)Br(12)], (VIII), containing the first reported fully halogenated quasi-planar pentacopper oligomer, the oligomers stack in a 5(3/2,1/2) stacking pattern as the highest nuclearity Cu(n)X(2n+2) oligomer compound known with isolated stacking. Bis(2-chloro-1-methylpyridinium) dodeca-μ-bromido-tetrabromidoheptacuprate(II), (C(6)H(7)ClN)(2)[Cu(7)Br(16)], (IX), contains the second heptacopper oligomer reported and consists of layers of interleaved oligomer stacks with a 7[(7/2,1/2)][(-9/2,-1/2)] pattern isomorphous with that of the known 1,2-dimethylpyridinium analog. All the oligomers reported here are inversion symmetric.
