Scuola di Scienze del Farmaco e dei Prodotti della Salute, Divisione di Chimica, Università degli Studi di Camerino, Via S. Agostino 1, 62032 Camerino (MC), Italy.
Inorg Chem. 2012 Sep 17;51(18):9775-88. doi: 10.1021/ic3011635. Epub 2012 Aug 24.
Coupling the rigid spacer 4,4'-bipyrazole (H(2)BPZ), in its anionic or neutral form, to different silver(I) salts allowed isolation of the novel coordination polymers [Ag(2)(BPZ)] (1) and [Ag(H(2)BPZ)(X)] (X = NO(3), 2; ClO(4), 3; BF(4), 4; PF(6), 5; CH(3)SO(3), 6; CF(3)SO(3), 7), which were fully characterized by infrared and emission spectroscopies, thermal analysis, and X-ray powder diffraction. The crystal structure of 1 consists of 2-D layers containing 1-D chains of Ag(I) ions bridged by exo-tetradentate bipyrazolato moieties. The crystal structures of the [Ag(H(2)BPZ)(X)] species 2-7 feature 1-D chains of [Ag(H(2)BPZ)] stoichiometry, along which the metal centers are bridged by exo-bidentate bipyrazolyl spacers. Contacts among adjacent chains are mediated by the counterions through nonbonding interactions involving the Ag(I) ions and the pyrazolyl N-H groups. Thermogravimetric analyses disclosed the good thermal stability of these materials, decomposing in the range 200-300 °C. Under UV irradiation at room temperature, all the species showed a yellow-green emission centered in the range 520-522 nm. When embedded into polyethylene disks, 1, 2, and 4-7 demonstrated their activity as topical antibacterial agents against suspensions of E. coli, P. aeruginosa, and S. aureus: complete reduction of the three bacterial strains was achieved in 24 h, reduction of S. aureus reaching ca. 90% in only 2 h. Biocidal action was expressed also by contact susceptibility tests.
将刚性间隔物 4,4'-联吡啶（H(2)BPZ）以其阴离子或中性形式与不同的银（I）盐偶联，允许分离出新型配位聚合物[Ag(2)(BPZ)]（1）和[Ag(H(2)BPZ)(X)]（X=NO(3)，2；ClO(4)，3；BF(4)，4；PF(6)，5；CH(3)SO(3)，6；CF(3)SO(3)，7），这些聚合物通过红外光谱和发射光谱、热分析和 X 射线粉末衍射进行了充分的表征。1 的晶体结构由二维层组成，包含一维链，其中 Ag(I)离子由外四齿联吡啶基部分桥接。[Ag(H(2)BPZ)(X)]物种 2-7 的晶体结构具有[Ag(H(2)BPZ)]化学计量的一维链，其中金属中心通过外双齿联吡啶基间隔物桥接。相邻链之间的接触通过非键相互作用介导，涉及抗衡离子和吡唑基 N-H 基团的 Ag(I)离子。热重分析表明这些材料具有良好的热稳定性，在 200-300°C 范围内分解。在室温下的紫外光照射下，所有物种都表现出以 520-522nm 为中心的黄色-绿色发射。当嵌入聚乙烯盘时，1、2 和 4-7 显示出它们作为针对大肠杆菌、铜绿假单胞菌和金黄色葡萄球菌悬浮液的局部抗菌剂的活性：三种细菌菌株在 24 小时内完全减少，金黄色葡萄球菌的减少仅在 2 小时内达到约 90%。接触敏感性测试也表达了杀菌作用。
