Synthesis, Crystal Structure and Property Studies on a Tetrachlorocuprate Salt of an Organic Cation

Abstract

Organic-inorganic hybrids provide an exciting opportunity to combine useful attributes of organic and inorganic materials within a single molecular scale composite. Thus, organic-inorganic salts become a relatively large structural family in which a number of interesting magnetic, optical, and electrical phenomena have been observed. [1][2][3][4] Among numerous robust and flexible synthetic strategies to obtain organic-inorganic salts, Orpen and Brammer groups 4-6 have used salts of anionic metal complexes with peripheral hydrogen-bond acceptor capability (and no hydrogen-bond donors) in which the relative orientation and location of the ions is controlled at least in part by M-Cl…HN (M=Pt, Pd) hydrogen bonding. This strategy affords diversity through modularity, with a wide variety of ions of various shapes, charges, and properties being available to replace either a cation or an anion. For example, Orpen group explored the consequences on the structures as a result of modifying the geometries of the anion (monatomic Cl-, square planar, trigonal bipyramidal, octahedral, and polymeric), 7-9 the type and orientation of the ligand hydrogen-bond acceptors, 10,11 and the location of the cation NH groups.12 Recently, our group obtained a tetrachlorocuprate salt of an organic cation,·H 2 O {DBPMF = 2,7-dibromo-9,9-(4-pyridylmethyl)fluorine}, where Cu-Cl…HN hydrogen bonding helps to form net works and stabilize the molecular structure. Herein, we wish to report the synthesis, crystal , F(000) = 5776, GOF = 0.939, R 1 = 0.0592, wR 2 = 0.0899. A displacement ellipsoid plot, with the atomic numbering scheme, is shown in Figure 1. 14 In the title compound, all of the bond lengths of Cu-Cl [2.2102(18)-2.2735(18) Å] are comparable to the similar organic-inorganic salts cited above.The most notable structure feature of the title compound is that there are many types of the intramolecular and intermolecular hydrogen bonds, potential weak C-H…Cl (Br), C- 2− anions and two [H 2 DBPMF] 2+ cations to form a short chain as shown in Figure 2. In the crystal lattice, these chains are staggered each other to form 3-dimension networks. All of the hydrogen bonds, intermolecular interactions and π…π stacking interactions stabilize the molecular structure.Fluorescence spectra of the title complex were measured on a F96-fluorospectrophotometer in DMF solution, as shown in Figure 3, which displays a broad emission band with the maximum intensity at λ = 367 nm in the DMF solution upon excitation at λ = 365 nm. Figure 4 gives the thermal analysis curve of the title compound. In Figure 4, there are mainly two exothermal peaks,