The synthesis and single crystal X-ray structure of the multifunctional acrylamide-derived ligand N-triazolylpropanamide (1, = NTPA) are reported. The title compound was prepared in 72 % yield by Michael addition of 1,2,4-triazole and acrylamide in the presence of Triton B (= trimethylbenzylammonium hydroxide) as catalyst.

Source of material 2-(1H-pyrazol-3-yl)pyridine (pypd)w as prepared accordingt o the literature methods [3,4].Am ixture of 2-(1H-pyrazol-3-yl) pyridine (pypd)(0.2 mmol), CuCl2 (0.2 mmol) and distilled water (10 cm 3 )was sealed in a25mLTeflonlined stainless-steelreactor, heated to 130°C and kept at constant temperature for 2days. Slow cooling to room temperature gave blue, block-shaped crystals of the title compound (yield 68%). Experimental detailsPseudo-symmetry problemss eem to influence the anisotropic displacement parameters [5]. DiscussionWith the rapid development of crystal engineering, more and more metal-organic complexes possessing various structural features have been synthesized [6]. Among the reported complexes, Cu(II) containing complexes have attracted considerable interests sinceC u(II)i sa ne ssentialt race elementf or life processes [7]. The penta-coordination of Cu(II) is very commonand usually presents asquare-pyramidal, atrigonal-bipyramidal geometry, or an distorted intermediate geometry. The title compound, [Cu 2 Cl 4 (C 8 H 6 N 3 ) 2 ], represents the first example of ab inuclear complex of Cu(II) with the chlorido and the 2-(1H-pyrazol-3-yl)-pyridine (pypd)ligand. The Cu(II)atom is five-coordinated, and the coordination sites are occupied by two Natoms provided by the chelating 2-(1H-pyrazol-3-yl)pyridine, as well as two asymmetrically bridging and one terminal chlorido ligands. The pypd ligand is bidentate through its pyridine and pyrazol Na toms, while the atomsN2/N5 do not participate in the coordination. The geometry of the CuCl 3 N 2 chromophore can be quantitatively characterisedusing theparameter t (t =(b-a)/60, where b is the largestbasal angleand a is the second in magnitude; t =0and 1 for perfect square-pyramidal and trigonal-bipyramidal geometries, respectively) [8]. Thecalculated value of t =0.06indicates that thecoordinationgeometryaroundthe metal centre, although intermediate between the two ideal polyhedrons, is closer to an elongated tetra-gonal pyramid with chlorido anions placed alternatively on equatorial and apical positions. As aresult, the geometry of the complex consists of two square pyramids sharing one base-to-apex edge,withparallel basal planes [9]. TheCu 2 Cl 2 core corresponds to an almost ideal rectangle as reflected from the Cl-Cu-Cl andCu-Cl-Cubonda nglesof9 0.49 and89.58°, respectively.