2,2′ : 6′,2″ : 6″,2‴-Quaterpyridine (qtpy): a versatile ligand in metallosupramolecular chemistry; crystal and molecular structures of [Ni(qtpy)(OH₂)₂][BF₄]₂, [Pd(qtpy)][PF₆]₂, [Cu₂(qtpy)₂][Pf₆]₂and [Ag₂(qtpy)₂][BF₄]₂

Synthesis and Characterization of a Ruthenium(II) Complex for the Development of Supramolecular Photocatalysts Containing Multidentate Coordination Spheres

“…The 1 H NMR spectrum in CD 3 CN of 7 + Zn shows 15 sharp signals in the aromatic and two in the aliphatic region, which could be assigned by H–H COSY measurements(Figure S14 and S15). The number of signals indicates C 2 symmetry, similar to [Zn(qpy)(OH 2 ) 2 ](BF 4 ) 2 reported by Constable et al Surprisingly, high‐resolution mass spectrometry gave no additional insight into the structure of the Zn II complex of 7 since no Zn‐containing species could be detected.…”

A planar silver complex of 2,2′:6′,2″:6″,2‴-quaterpyridine

“…In [Ag 2 (qtpy) 2 ][BF 4 ] 2 the Ag-N bond distances are in the range 2.223(16)-2.409(13) Å [3], close to the present findings.…”

“…Comparison of our results with the data previously reported for the Ag(I)/qtpy system [3] confirms that compounds of the same composition can assembly in different ways in the solid state, depending on the nature of the counterion and on the crystallization conditions. Other examples of this behavior concern the silver(I) complexes of 4 0 -thiomethyl-2,2 0 :6 0 ,2 00 -terpyridine, whose structures change from aggregated mononuclear or dinuclear units to polynuclear supramolecular spirals as a function of both the anion (PF À 6 , CH 3 COO À , BF À 4 or ClO À 4 ) and the solvent (acetonitrile or nitromethane) [12].…”

“…In a few cases, however, coordinated qtpy has been found in a nonplanar arrangement, as in [M(qtpy) 2 ] 2+ , M = Fe, Ni, Zn, where it behaves as terdentate [2], or in the dinuclear cationic copper(I) and silver(I) complexes [M 2 (qtpy) 2 ] [BF 4 ] 2 where the central metal ion shows a pseudotetrahedral coordination geometry with bridging qtpy ligands (deviation from planarity up to 40°) [3]. The resulting double helicate structure was rationalized with the preference of d 10 metal ions for a tetrahedral arrangement of the four donor atoms.…”

Diastereoselective Assembly of Helicates Incorporating a Hexadentate Chiral Scaffold

“…The terminal pyridine donors are too distant from the metal centre for the Ag···N interactions to be considered important [Ag1···N12Ј 3.439(10), Ag2···N6Ј 3.166 (11) , the Ag···Ag separation is 3.2223(8) Å, less than the sum of the van der Waals radii (3.44 Å), but at the longer end of what might be considered a metallophilic interaction. [44] Nonetheless, this interaction may be sufficient to control the organization of the two ligands and is similar to the distances of 3.107(2) Å [45] and 3.230(2) Å [46] , and the disilver helicate lacks the pseudo-symmetry possessed by the diiron (see insert in Figure 9) and dizinc species. 2+ cation, the two bpy domains of a given ligand are distinct.…”