Reger Daniel L, Semeniuc Radu F, Silaghi-Dumitrescu Ioan, Smith Mark D
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA. Reger@ mail.chem.sc.edu
Inorg Chem. 2003 Jun 16;42(12):3751-64. doi: 10.1021/ic034039r.
The reactions between silver tetrafluoroborate and the ligands 1,2,4,5-C(6)H(2)CH(2)OCH(2)C(pz)(3) (L1, pz = pyrazolyl ring), o-C(6)H(4)CH(2)OCH(2)C(pz)(3) (L2), and m-C(6)H(4)CH(2)OCH(2)C(pz)(3) (L3) yield coordination polymers of the formula (C(6)H(6)(-)(n)CH(2)OCH(2)C(pz)(3)(AgBF4)(m))( infinity ) (n = 4, m = 2, 1; n = 2, ortho substitution, m = 1, 2; meta substitution, m = 2, 3). In the solid state, L2 molecules dimerize by a pair of C-H.pi interactions, forming an arrangement that resembles the tetratopic ligand L1. In the solid-state structure of 1, each silver atom is kappa(2)-bonded to two tris(pyrazolyl)methane units from different ligands with the overall structure a polymer made up from 32-atom macrocyclic rings formed by bonding tris(pyrazolyl)methane groups from nonadjacent positions on the central arene rings to the same two silver atoms. In 2, each silver is bonded to two tris(pyrazolyl)methane units in the same kappa(2)-kappa(2) fashion as with 1, forming a polymer chain. The chains are organized into dimeric units by strong face-to-face pi-pi stacking between the central arene rings making bitopic L2 act as half of tetratopic L1. The chains in both structures are organized by weak C-H.F hydrogen bonds and pi-pi stacking interactions into very similar 3D supramolecular architectures. The structure of 3 contains three types of silvers with the overall 3D supramolecular sinusoidal structure comprised of 32-atom macrocycles. Infrared studies confirm the importance of the noncovalent interactions. Calculations at the DFT (B3LYP/6-31G) level of theory have been carried out on L2 and also support C-H.pi interactions. Electrospray mass spectral data collected from acetone or acetonitrile show the presence of aggregated species such as (L)Ag(2)(BF(4)) and (L)Ag(2), despite the fact that (1)H NMR spectra of all compounds show that acetonitrile completely displaces the ligand whereas acetone does not.
四氟硼酸银与配体1,2,4,5-C(6)H(2)CH(2)OCH(2)C(pz)(3)(L1,pz = 吡唑基环)、邻苯二酚CH(2)OCH(2)C(pz)(3)(L2)和间苯二酚CH(2)OCH(2)C(pz)(3)(L3)反应生成通式为(C(6)H(6)(-)(n)CH(2)OCH(2)C(pz)(3)(AgBF4)(m))( infinity )的配位聚合物(n = 4,m = 2,1;n = 2,邻位取代,m = 1,2;间位取代,m = 2,3)。在固态中,L2分子通过一对C-H.pi相互作用二聚,形成类似于四齿配体L1的排列。在1的固态结构中,每个银原子以kappa(2)键合到来自不同配体的两个三(吡唑基)甲烷单元,整体结构是由32原子大环组成的聚合物,该大环通过将中心芳烃环上不相邻位置的三(吡唑基)甲烷基团与相同的两个银原子键合而成。在2中,每个银以与1相同的kappa(2)-kappa(2)方式键合到两个三(吡唑基)甲烷单元,形成聚合物链。这些链通过中心芳烃环之间强烈的面对面pi-pi堆积组织成二聚单元,使双齿L2起到四齿L1的一半作用。两种结构中的链通过弱C-H.F氢键和pi-pi堆积相互作用组织成非常相似的3D超分子结构。3的结构包含三种类型的银,整体3D超分子正弦结构由32原子大环组成。红外研究证实了非共价相互作用的重要性。在DFT(B3LYP/6-31G)理论水平上对L2进行了计算,也支持C-H.pi相互作用。从丙酮或乙腈收集的电喷雾质谱数据显示存在聚集物种,如(L)Ag(2)(BF(4))和(L)Ag(2),尽管所有化合物的(1)H NMR光谱表明乙腈完全取代了配体,而丙酮则不然。