Silver coordination polymers with remarkably high packing coefficients

Abstract

Silver meso-and rac-tartrate and silver squarate have been synthesized, and the crystal structure of a new polymorph of the latter is reported. Three reaction products of these silver salts with pyrazine have been obtained and structurally characterized: From silver squarate, a chain polymer with linear coordination of Ag(I) by two pyrazine ligands is formed, whereas the silver tartrates yield solids in which the inner coordination sites around the metal are only partially occupied by N donors; in contrast to expectation, oxygen coordination prevails. All the four new Ag(I) coordination compounds reported show high packing coefficients in the range between 0.789 and 0.885. In order to put these results into a meaningful context, packing coefficients for the crystal structures of almost 30,000 compounds retrieved from the Cambridge Structural Database have been determined. Tartrates pack significantly closer than pyrazine complexes or metalcontaining compounds in general. The exceptionally high packing coefficient of the new polymorph of silver squarate is due to stacking of anions and concomitant AgÁÁÁAg contacts, both along the shortest lattice parameter which amounts to only 3.3990(9) Å .

Polynuclear and polymeric squarato-bridged coordination compounds

“…117 The bonding modes μ 1,1,2,2,3,4 -(IX) and μ 1,1,2,2,3,3 -(X) were obtained in the complexes K 4 ij(Mo 4). 78,120,121 Table 4 Polynuclear metal complexes and polymeric coordination compounds with μ 3 -μ 8 squarato-bridging bonding modes Complex or complex ion Complex no.…”

An Acetylacetonate or a Pyrazole? Both! 3-(3,5-Dimethyl-pyrazol-4-yl)pentane-2,4-dione as a Ditopic Ligand

“…Table compiles the Ag···Ag distances in the five symmetrically independent aggregates in 3a , 3b , and 3c . Short Ag···Ag contacts are generally referred to as “argentophilic”, − and this type of interactions has recently been reviewed . More specifically, pyrazolyl-bridged Ag triangles represent a rather well-established oligonuclear aggregate: In the CSD database, , coordinates for 43 well-ordered and error-free occurences of this fragment are available, with an average length for the pyrazolyl-bridged edges of 3.469 Å.…”

Alkali metal halogenides coordination compounds with hexamethylenetetramine

“…The research of compounds containing these cations, their ionic antagonists (like other alkaline metals) with anions existing in body fluids is thus of great importance, as they affect the sodium-potassium pump. In addition, recently, an increasing interest is put on construction of dinuclear, multinuclear and polymeric coordination compounds [24][25][26][27] created by self-assembly [28] of the components [29][30][31][32].…”