Coordination complexes of copper(II) with herbicide-trichlorophenoxyacetate: Syntheses, characterization, single crystal X-ray structure and packing analyses of monomeric [Cu(γ-pic)3(2,4,5-trichlorophenoxyacetate)]·H2O, [trans-Cu(en)2(2,4,5-trichlorophenoxyacetate)2]·2H2O and dimeric [Cu2(H2tea)2(2,4,5-trichlorophenoxyacetate)2]·2(H2O)