A New Silver(I) Aggregate Having an Octagonal Ag₄S₄ Core Where μ₃‐S Bonding Interactions Lead to a Nanotube Assembly that Exhibits Quasiaromaticity

Abstract

Silver(I) chloride reacts with 2‐mercapto‐3,4,5,6‐tetrahydropyrimidine (StpmH2, C4H8N2S) in DMSO with excess triethylamine to give a complex of formula {[Ag4Cl4(μ3‐StpmH2)4]n} (1). The product was characterized by elemental analyses, FTIR far‐IR, UV/Vis, and 1H and 109Ag NMR spectroscopic techniques. The 109Ag NMR spectroscopic data of the complexes {[Ag6(μ2‐Br)6(μ2‐StpmH2)4(μ3‐StpmH2)2]n} (2) and {[Ag4(μ2‐StpmH2)6](NO3)4}n (3) are also reported here for comparison. Crystal structure of complex 1 was determined by X‐ray diffraction at 100(1) K. Complex 1, C4H8AgClN2S, crystallized in the tetragonal system, space group P4cc, a = 15.7761(9) Å, b = 15.7761(9) Å, c = 6.9624(8) Å, V = 1732.8(2) Å3, Z = 2. Each metal ion is bonded to one terminal Cl atom and three μ3‐S atoms from three StpmH2 ligands. Four silver ions are bridged by four sulfur atoms forming an octagonal Ag4S4 core. Each AgI ion of one core is also bridged to an AgI ion of another core through a sulfur atom, which forms an infinite nanotube structure. A computational study utilizing the method of nucleus‐independent chemical shifts (NICS) showed that the Ag4S4 core exhibits strong quasiaromaticity at the geometric cage center. To the best of our knowledge, this is the first example of an AgI cluster that presents quasiaromaticity and stacking interactions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Poly[bis(μ2-2-aminopyrazine-κ2N1:N4)(μ2-nitrato-κ2O:O)(nitrato-κ2O,O′)disilver(I)]: an achiral two-dimensional coordination polymer forming chiral crystals

“…The bond angles around Ag1 and Ag2 open up from the ideal tetrahedral angle to 145.84 (14) and 150.84 14, respectively, while the remaining angles around Ag1 and Ag2 are in the ranges 85.20 (12)-125.32 (12) and 49.89 (9)-113.25 (12) , respectively. The Ag-N and Ag-O bond lengths (Table 1) are comparable to those in related compounds (Fan et al, 2007;Oxtoby et al, 2002;Turner et al, 2005;Withersby et al, 1997;Zartilas et al, 2007). There are also weak AgÁ Á ÁC interactions with AgÁ Á ÁC distances in the range 3.314 (4)-3.322 (4) Å , which fall in the secondary bonding range (the sum of the van der Waals radii of Ag and C is 3.42 Å ; Mascal et al, 2000).…”

Synthesis, structural characterization and biological study of new organotin(IV), silver(I) and antimony(III) complexes with thioamides

“…3 ] with X = Cl (18), Br (19), I (20) where STHPMH 2 = 2-mercapto-3,4,5,6-tetrahydro-pyrimidine, TPTP = tri(p-toly)phosphine [22][23][24]27]. …”

“…With the aim to synthesize new antitumor agents based on organotin(IV), silver(I) or antimony(III) compounds we studied the interaction of R 3 SnCl and R 2 SnCl 2 (R = phenyl-, n-butyl-, methyl-) [17][18][19][20][21], AgX (X = NO 3 , Cl, Br, I) [22][23][24] or SbCl 3 [25,26] with the thioamides 5-chloro-2-mercapto-benzothiazole (CMBZT), 2-mercaptobenzothiazole (MBZT), 2-mercapto-thiazoline (MTZD), 2-mercapto-benzoxazole (MBZO), 2-mercapto-benzimidazole (MBZIM), 5-ethoxy-2-mercapto-benzimidazole (EMBZ-IM), 2-mercapto-pyrimidine (PMTH), 2-mercapto-3,4,5,6-tetrahydro-pyrimidine (STPMH 2 ), 2-mercapto-nicotinic acid (H 2 MNA). In case of silver(I) complexes tri(p-toly)-phosphine (TPTP) was, also, used as ligand [27].…”

catena-Poly[bis[silver(I)-μ2-4,4′-bipyridine-κ2N:N′] naphthalene-2,6-dicarboxylate tetrahydrate]: self-assembly of a supramolecular frameworkviacoordination bonds and supramolecular interactions

“…In the past few years, the development of supramolecular self-assembly has allowed the possibility of the rational design and preparation of supramolecular architectures through noncovalent interactions, in which it is crucial to meet both geometric and energetic considerations (Pedireddi et al, 1996). Doubtless, the hydrogen bond is the most familiar secondary force in supramolecular assembly, since it is a moderately directional intermolecular interaction that may control molecular packing (Kolotuchin et al, 1995;Zartilas et al, 2007), and many reports have focused on studies of the hydrogen bond (Li et al, 2006;Sun et al, 2003;Lough et al, 2000;Massoud & Langer, 2009). Compared with the hydrogen bond, C-HÁ Á Á andinteractions have been somewhat less well covered (Blake et al, 2000;Goodgame et al, 2002).…”