New Coordination Polymers and Porous Supramolecular Metal Organic Network Based on the Trinuclear Triangular Secondary Building Unit [Cu₃(μ₃-OH)(μ-pz)₃]²⁺and 4,4′-Bypiridine. 1°

Abstract

The trinuclear triangular CuII complex [Cu3(μ3-OH)(μ-pz)3(HCOO)2(Hpz)2] (Hpz = pyrazole) reacts with 4,4′-bipyridine (bpy) yielding a two-dimensional (2D) waved sheets, two three-dimensional (3D) coordination polymers (CPs), as well as a hexanuclear CuII cluster, depending on the reagent ratios and reaction conditions. Single crystal X-ray diffraction (XRD) determinations point out that, while CPs crystal structures are not porous, the hexanuclear CuII clusters are packed in the solid state generating a stable porous 3D supramolecular network, where two kinds of perpendicular, hydrophobic channels (ca. 4.83 × 5.86 Å2 and 4.99 × 4.79 Å2, corresponding to the 24.7% of the total crystal volume) are present. In the “as-synthesized” compound, channels of one kind are empty, while the other ones are occupied by guest bpy molecules which can be removed by soaking the crystals in suitable solvents (benzene, toluene, c-hexane) maintaining intact the crystal skeleton. Moreover, two of the above complexes act as catalysts (or catalyst precursors) in the peroxidative oxidation of cyclohexane.

New Syntheses, Analytic Spin Hamiltonians, Structural and Computational Characterization for a Series of Tri-, Hexa- and Hepta-Nuclear Copper (II) Complexes with Prototypic Patterns

“…The triangular copper complexes with a hydroxy-or oxo-trinuclear bridge were obtained usually by the pyrazole deprotonation in the presence of a base [16][17][18], while in the case of using carboxylates copper salts, the pyrazole deprotonation is favored by the presence of carboxylate ions. Our compound 1 parallels literature results in terms of synthetic procedures and outcomes [26,27].…”

Trinuclear copper(ii) pyrazolate compounds: a long story of serendipitous discoveries and rational design

“…Considering only ionic species, the CCDC database reports 10 type A and 12 type C compounds. In the case of type A derivatives, the uncoordinated monocation is tetra--n--butylammonium (compounds 6--7, 34 8--9, 35 10 36 and 11 37 ), triethylammonium (compound 12 38 ), or (triphenylphosphino)iminium (compounds 13 34 and 14--15 36 ), while in the case of type C the uncoordinated monoanion is chloride (compounds 16 39 and 17 40 ), hydroxide (compounds 18--21 41 and 22--23 42 ), trifluoromethanesulfonate (compounds 2, 31 , 24 37 and 25 43 ) and dicyano(nitro)methanide (compound 26 44 ).…”

“…In detail, 18 derivatives bear inorganic anions, actually nitrate (compounds 27, 31,45 and 34 50 ), bromide, (compound 35 51 ), perchlorate (compounds 36 31 and 37 52 ), trifluoromethanesulfonate (compounds 38 31 and 39--41 43 ), sulfate (compound 42 31 ), phosphonate (compound 43 47 ) and sulfate plus nitrate (compound 44 53 ). Organic anions are instead present in 36 cases, actually in derivatives bearing formate (compounds 45--46 41 and 47 54 ), acetate (compounds 48--49 42 and 50 55 ), trifluoroacetate (compound 51 31 ), propanoate (compounds 52--53, 7 54 42 and 55 54 ), ge 3 of 31 CrystEngComm…”

Investigation on the interconversion from DMF-solvated to unsolvated copper(ii) pyrazolate coordination polymers

“…These trinuclear complexes self-assemble in hexanuclear clusters through carboxylate bridges and form extended 1-D, 2-D or 3-D CPs or supramolecular networks, displaying intriguing catalytic activity in the cycloalkane oxidation to alcohols. [27][28][29][30][31][32][33][34][35][36][37][38][39][40]41 Completely different results were obtained when Cu(II) carboxylates were reacted with pzH in MeCN, yielding the pale-pink 1-D CP [Cu(µ-pz) 2 •H 2 O] n independently from the carboxylate employed (Scheme 1). [42][43][44] This compound reversibly loses water, yielding [Cu(µ-pz) 2 ] n .…”