Structural Diversity of Silver(I) 4,6-Dipyridyl-2-Aminopyrimidine Complexes:  Effect of Counteranions and Ligand Isomerism

Abstract

Using two ligands, 4,6-bis(2-pyridyl)-2-aminopyrimidine (L1) with two N,N'-chelating sites and 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine (L2) (as the isomer of L1) containing one chelating site and one bridging unit, a series of novel Ag(I) complexes varying from zero- to two-dimensions have been prepared and their crystal structures determined via single-crystal X-ray diffraction. The two ligands are employed for the first time in coordination chemistry. The structures of compounds 1-3 are directed by the counteranions adopted in the reaction system: The reaction of L1 with AgNO3 yielded a dimer [Ag2L12](NO3)2 (1). The reaction of L1 with AgCF3SO3 led to a one-dimension "V-shaped" chain {[AgL1](CF3SO3)}n (2). When AgSCN was used, a one-dimension ladder {[Ag2L1(SCN)2].H2O}n (3) was obtained. While ligand L2 reacted with AgNO3, a two-dimension {[Ag2(L2)2](NO3)2.H2O}n (4) was prepared with the help of an argentophilic interaction. Compounds 1-4 display room-temperature photoluminescence.

Synthesis and crystallographic characterization of a six coordinate Cu(II) complex based on hexamethylenetetramine ligand

“…The control of structure and topology of assemblies is one of the major goals in supramolecular chemistry. The rational design and controlled synthesis of metal-organic frameworks (MOFs) is currently of great interest in the realm of crystal engineering and supramolecular chemistry because of not only their intriguing structural diversities [3][4][5] and interesting topologies [6] but also their potential uses as functional materials [7][8][9][10]. In this field, the effective and facile approach for the synthesis of such MOFs is still the appropriate choice of well-designed organic ligands as bridges or terminal groups (building blocks) with metal ions or metal clusters as nodes, which, so far, has been at an evolutionary stage with the current focus mainly on understanding the factors to determine the crystal packing as well as exploring relevant potential properties.…”

Syntheses and structures of two noncentro symmetric inorganic–organic composite materials based on metal sulfate and 4,4′-bipyridine (M=Ni, Fe)

“…Although isolated, monodentate, and briding (l 2 , l 3 and l 4 ) sulfate anions have been previously found in coordination complexes, a majority of them adopt only one kind of coordination mode in a single compound [3][4][5][6][7][8][9][14][15][16][17][18][19][20][21][22][23][24][25][26]. It is rare to observe that two or more kinds of coordination modes co-existing in one crystal structure.…”

“…Careful design of these materials can provide substances with unusual structural characteristics as well as extraordinary physical properties [1,2]. Some simple coordination anions, such as NO À 3 ; ClO À 4 ; SO 2À 4 and PO 3À 4 , have been found to be efficient in influencing the structures of hybrid materials [3][4][5][6], and they play significant roles in the assembly of small molecular components. One approach among these efforts has exploited the bifunctional organoamine ligand 4,4 0 -bipyridine, where these simple anions act as co-ligands.…”

Three 1D copper(I/II) complexes of 4,6-dipyridyl-2-aminopyrimidine: Effect of the ligand isomerism on the structural motif

“…In this paper, we designed and synthesized three ligand isomers: 4,6-bis(2-pyridyl)-2-aminopyrimidine (H 2 L1), 4-(2-pyridyl)-6-(3-pyridyl)-2-aminopyrimidine (H 2 L2), 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine (H 2 L3) (Scheme 1) [7] and used them to react with CuCl 2 AE 2H 2 O to construct coordination polymers. Our aim is to investigate how the structural motif of the resulting copper coordination polymers could be manipulated by the ligand isomers.The three ligand isomers: H 2 L1, H 2 L2 and H 2 L3 are five-dentate, multifunctional ligands and their coordination chemistry was not explored widely, except several silver(I) compounds of H 2 L1 and H 2 L2 were reported in our recent work [8]. The three isomers all have a N,N 0 -chelating site with the capability of binding one metal center, but the different pyridine substituent groups on the six-position of pyrimidine ring make the ligands exhibit different bridging modes (Scheme 1).…”

“…The three ligand isomers: H 2 L1, H 2 L2 and H 2 L3 are five-dentate, multifunctional ligands and their coordination chemistry was not explored widely, except several silver(I) compounds of H 2 L1 and H 2 L2 were reported in our recent work [8]. The three isomers all have a N,N 0 -chelating site with the capability of binding one metal center, but the different pyridine substituent groups on the six-position of pyrimidine ring make the ligands exhibit different bridging modes (Scheme 1).…”