Molecular “Multi-rod Cable” {[Co(NC5H4-CH=CH-C6H4-CH=CH-C5H4N)(HCOO)2]8}n: A Novel Supramolecular Architecture by Cooperation of Coordination and Stacking Interactions

Abstract

The cobalt-formate coordination polymers {[Co-(bpyph)(HCOO) 2 ] 8 } n (1) (bpyph = 1,4-bis(2-(4-pyridyl)ethenyl)benzene) and {[Co(HCONH 2 ) 2 (HCOO) 2 ]} n (2) have been prepared by interaction of Co(NO 3 ) 2´6 H 2 O in formamide solution with generation of formate anion by hydrolysis of the solvent. Coordination polymer 1 reveals an unprecedented example of ªmolecular multi-rod cableº architecture, in which eight single ªmolecular wiresº {[Co(bpyph)]} n are interlinked by bridging formate anions to give infinite octameric chains. The formate groups adopt mono-, and biand tridentate bridging and chelate modes of coordination (Co±O 1.966±2.134 A Ê ). The coordination geometry around the cobalt atoms is essentially dominated by the demands for most effective packing of parallel situated polycyclic aromatic ligands, with extensive CH´´´p, or edge-to-face stacking interactions within the single octameric chain as well as between the closest neighbours (C´´´C separations within this stack are ca. 3.50 A Ê ). Ein mehradriges molekularesKabel ± eine neuartige supramolekulare Architektur durch Kooperation von Koordinations-und Stapelwechselwirkung Inhaltsu È bersicht. Die Koordinationspolymere der Cobaltformiate {[Co(bpyph)(HCOO) 2 ] 8 } n (1) (bpyph = 1,4-bis(2-(4-pyridyl)ethenyl)benzol) und {[Co(HCONH 2 ) 2 (HCOO) 2 ]} n (2) wurden durch Reaktion von Co(NO 3 ) 2´6 H 2 O mit einer Formamidlo È sung unter Bildung des Formiatanions durch Hydrolyse des Lo È sungsmittels synthetisiert. Das Koordinationspolymer 1 zeigt eine neuartige Architektur eines molekularen, mehradrigen Kabels, in welchem acht ªmolekulare Dra È hteº {[Co(bpyph)]} n durch verbru È ckende Formiatanionen verknu È pft sind. Die Formiatgruppe bildet ein-, zwei-oder dreiza È hlige verbru È ckende und chelatisierende Koordinationsmodi aus (Co±O 1.966±2.134 A Ê ). Die Koordinationsgeometrie des Cobaltatoms wird im wesentlichen dominiert durch effektive Packung der parallel angeordneten polycyclischen aromatischen Liganden mit ausgepra È gten CH´´´p-Wechselwirkungen oder Kanten zu Fla È chen Stapelungen innerhalb der einzelnen oktameren Ketten als auch zwischen den engsten Nachbarn (C´´´C-Absta È nde innerhalb der Stapel betragen ca. 3.50 A Ê ).

Poly[[diaquabis[μ2-2-(4-pyridinio)propane-1,3-dionato-κ2O:O′]cobalt(II)] dinitrate]

“…2). It is interesting to note that the topology and shape of the network are very similar to those observed in the 3d-metal (Co, Ni) formate complexes with urea (Koyano et al, 1992) and formamide (Domasevitch et al, 2002). This also suggests close structural resemblance of the formate and 1,3-dionate (as the vinylogous formate anion) groups as bridging blocks for the design of polymeric coordination compounds.…”

Luminescence induced by strong cation–anion π–π interactions in crystals of viologen analogues

“…In the absence of special intermolecular interactions, the crystal structure of these compounds is usually disordered. 11 That may explain why only the few number of crystal structures with the 1,4-bis[2-(4-pyridyl)ethenyl]benzene core have been deposited at the Cambridge Crystallographic Data Centre, whereas for related 4,4 0 -bipyridines more than 3000 structures have been deposited, while the former ligand is no less significant 16 for crystal engineering than the second one and also is synthetically available.…”

Cadmium(II) iodide and thiocyanate complexes adopted by polycyclic 1,4-bis(pyridazin-4-yl)benzene: interplay of coordination and π–π stacking interactions

“…Slippedstacking interactions represent a common type of supramolecular force for the structure of coordination compounds incorporating heteroaromatic ligands (Janiak, 2000). Extension of the aromatic linkage has a pronounced impact on the coordination architecture (Khlobystov et al, 2001), while leading to stabilization of a pattern favouring parallel alignment of the organic modules with multipleor C-HÁ Á Á interactions (Domasevitch et al, 2002). The role of such weaker bonding (and its reliability as a special design tool) becomes even more appreciable when considering flexible coordination systems readily adaptable to the needs of interaromatic stacking (Roesky & Andruh, 2003).…”