The crystal structures of new red (1) and orange (2) polymorphs of chloro(2,2′:6′2″-terpyridine)-platinum(II) chloride dihydrate, [Pt(terpy)Cl]Cl·2H2O, have been determined by single crystal X-ray diffraction. Compound 1 packs in a one-dimensional stacking structure with two unique intermolecular Pt···Pt distances (3.3278(5) Å, 3.4444(5) Å). The principal difference between this red polymorph and a previously reported yellow polymorph is in the cation stacking motif. This red polymorph has two alternating short intermolecular Pt·· ·Pt distances while the yellow polymorph has one long and one short Pt···Pt distance. Channels between the cation stacks are occupied by a hydrogen-bonding network of water molecules and chloride anions. This red polymorph has a cation stacking motif similar to those found in a diverse collection of structures with different counterions and solvates of the chloro(2,2′:6′2″-terpyridine)-platinum(II) cation. The orange polymorph 2 possesses a stacking motif with two alternating long intermolecular Pt···Pt distances (4.2169(4) Å, 5.1582(4) Å). The hydrogen-bonding network involving the chloride counterions and water molecules differs significantly from either the red or yellow polymorphs as well. Structure 1: monoclinic, P 21/c, a = 12.2630(14) Å, b = 6.7459(8) Å, c = 20.121(2) Å, β = 105.018(2), V = 1,607.7(3) Å3, Z = 4, R 1 = 0.0338, wR 2 = 0.0665. Structure 2: monoclinic, P 21/c, a = 8.0236(7) Å, b = 12.9393(1) Å, c = 15.847(2) Å, β = 101.068(7), V = 1,614.6(3) Å3, Z = 4, R 1 = 0.0181, wR 2 = 0.0377. Graphical Abstract: The crystal structures of new red (1) and orange (2) polymorphs of chloro(2,2′:6′2″-terpyridine)-platinum(II) chloride dihydrate, [Pt(terpy)Cl]Cl·2H2O show that the red polymorph stacks with two unique intermolecular Pt···Pt distances (3.3278(5) Å, 3.4444(5) Å) while the orange polymorph has no intermolecular Pt···Pt contacts less than 4.2 Å.
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Red None [PtCl3(DMSO)]- 283 P21/c a = 6.716(1) 3.338(1) 3.419(1) 167.36(3) 180 Acknowledgments This work was supported by the Endowed Chair in the Sciences, School of Humanities, Arts, and Sciences, St. Catherine University. The authors acknowledge the National Science Foundation Major Research Instrumentation Award #1125975 for funding the acquisition of the Rigaku XtaLAB mini X-ray diffractometer used for data collection of the orange polymorph. The authors also acknowledge Dr. Victor G. Young Jr., Director of the X-ray Crystallographic Laboratory of the Department of Chemistry, University of Minnesota where data was collected for the red polymorph, and Dr. Lee Daniels, Director of Small-Molecule Crystallography at Rigaku Americas Corp. for sharing their crystallographic expertise.
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- X-ray crystallography