Quest for Second-Harmonic-Generation-Active Coordination Polymers:  Synthesis and Properties of Silver(I) Pyrimidinolates

Abstract

In the search for coordination compounds showing significant second harmonic generation (SHG) activity, reaction of Ag(I) ions with the 4-hydroxypyrimidine (4-Hpymo) and 5-nitro-2-hydroxypyrimidine (HNP) ligands generated four crystalline 1D polymers, Ag(4-pymo)‚nH 2 O (n ) 2.5, 0), Ag(NP)(NH 3 ), and Ag(NP), the latter two crystallizing in acentric space groups. Their synthesis, complete characterization, and structural determination, by conventional single-crystal and laboratory X-ray powder diffraction methods, are presented and discussed in the frame of diazaaromatic-ligand-and metal-containing species. XRPD has also allowed the detection of the polyhydrated, elusiVe Ag(4-pymo)‚nH 2 O (n ) 2, 3) species. Powders of Ag(NP) have shown an SHG activity close to that of standard urea. By applying the geometrical model proposed by Zyss, it is shown that the NP ligand is a highly promising chromophore, the oxo and nitro functionalities cooperatively promoting a high hyperpolarizability.

Tuning the Structural and Magnetic Properties of Thermally Robust Coordination Polymers

“…The N,N‘-exo-bidentate coordination mode is, by far, the most common one adopted by the parent 2-pymo ligand ,, yet not by its 5-nitro derivative. The latter, in the few cases in which has been employed, has not infrequently shown its exocyclic oxygen atom coordinated to the metal center …”

“…Notably, in the case of [Ni(2-pymo) 2 ] n , which is not isomorphous with the analogues of Co(II) and Zn(II), a diamondoid network can be nevertheless recognized when just the overall connectivity is taken into consideration . At variance, the homoleptic [M(NP) 2 ] n derivatives (M = Co, Zn; NP = 5-nitro-2-pyrimidinolate; see Chart ) deviate from this trend: indeed, they crystallize as two-dimensional slabs in which the metal center shows a MN 3 O stereochemistry 34a 3 Representation of the three-dimensional diamondoid motif in [M(5-X-2-pymo) 2 ] n .…”

Structures from Powders: Polynuclear Hg(II) Complexes Containing the Flexible Bisimidazolylmethane Ligand

“…Starting from simple heteroaromatic anions, such as pyrazolate, imidazolate, and pyrimidinolate, we further increased the complexity of the polytopic N-ligands employed in the formation of monomeric, oligomeric, and polymeric species. For example, our recent results of substituted triazines, , scorpionates, and substituted heterocycles have allowed us to prepare and characterize a number of functional species, ranging from catalytically active (soluble) oligomers to extended solids capable of molecular sensing and recognition . Recently, when the isolated material was not available as single crystals of suitable quality, the structural characterization was performed employing state-of-the-art powder diffraction methods coupled with 13 C cross polarization−magic angle spinning (CP-MAS) NMR spectroscopy …”

Ligand and Counterion Control of Ag(I) Architectures: Assembly of a {Ag8} Ring Cluster Mediated by Hydrophobic and Ag···Ag Interactions

“…Motivation for such work is provided by the properties of a wide variety of multinuclear coordination compounds, both designed and "discovered", which have exhibited phenomena including catalysis of organic reactions 9 and optical properties. [10][11][12] Silver(I) coordination compounds have attracted considerable interest in inorganic and supramolecular chemistry because of the coordinative flexibility of Ag(I): [13][14][15][16] as well as linear, trigonal, tetrahedral, or octahedral coordination modes, Ag(I) centers can form Ag‚‚‚Ag bonding interactions due to argentophilicity. 17 Given this structural versatility (or unpredictability!…”