Structural Analysis and Magnetic Properties of the 1D and 3D Compounds [M_n(dca)_2nbipym] (M = Mn, Cu; dca = Dicyanamide; bipym = Bipyrimidine; n = 1, 2)

Abstract

Compounds [Mn(dca)2bipym] (1), [Cu2(dca)4bipym] (2), and [Mn2(dca)4bipym] (3) have been synthesized and structural (2, 3) and magnetically characterized. Compound 1 is isomorphous with [Mn(dca)2bipy]. Compound 2 crystallizes in the monoclinic P21/c space group, Z = 4, with a = 7.5609(9), b = 11.477(42), and c = 11.792(2) Å and β = 106.565(6)°. Compound 3 crystallizes in the monoclinic system, space group P21/n, with a = 7.396(3) Å, b = 11.498(7) Å, and c = 12.349(9) Å and β = 106.61(5)°. While compound 1 is one-dimensional, with the manganese(II) ions bridged by double μ1,5-dicyanamide ligands, the structural arrangement in compounds 2 and 3 is three-dimensional based on ladder-like moieties. These units, whose steps are bipym groups, extend through μ1,5-dca bridges and are connected to another four on the plane perpendicular to the extension of the ladders to form the 3D arrangement. Magnetic susceptibility measurements show antiferromagnetic couplings in all cases, increasing for 1, 3, and 2, respectively.

Two new 1-D dicyanamide bridged polymeric complexes [Mn(μ1,5-dca)2(salicyh)2]n and {[Ni(μ1,5-dca)(TTA)](ClO4)}n (dca=dicyanamide, ; salicyh=salicylic hydrazide; TTA=triethylenetetramine): Synthesis, structures and magnetic studies

“…The solid state of complexes depict several ν CN bands at 2303, 2240, 2172 cm −1 for 1 and 2306, 2229, 2160 cm −1 for 2 which are attributed to ν sym + ν asym (CN), ν asym (CN) and ν sym (CN) modes. All data are in good agreement with the literature [23], [34], [35], [36], [37], [38] and [39]. Relative to ν (N(CN) 2 ) values of the free ligand (2287, 2229 and 2181 cm −1 ), those of complex 1 and complex 2 show higher frequency shifts, due to the bridging coordination mode of dca in the complexes.…”

Synthesis, Crystal Structures, and Magnetic Properties of Ternary M(II)-Dicyanamide-hydroxypyridine Complexes

“…In recent years, much attention has been devoted to dicyanamide-anion-(dca-) bridged coordination polymers [30][31][32][33][34][35][36][37][38][39][40][41][42] for the large variety of magnetic properties, especially the -M(dca) 2 series of compounds, which have isomorphous rutile-like structure, display ferromagnetism (Co, Ni) [43][44][45][46], spin-canted antiferromagnetism (Cr, Mn, Fe) [47,48], and paramagnetism (Cu) [45,46]. Of further importance, from a structural perspective, when auxiliary L ligands are introduced to the ternary M II -dca-L systems, different coordination architectures, such as mononuclear and dinuclear compounds [49], 1D chains [50][51][52][53][54][55][56][57][58], 2D (4,4) or (6,3) [59][60][61][62][63] sheets, and 3D network topologies [64][65][66][67], could be constructed (Scheme 1).…”

Syntheses, structures and magnetic properties of two novel 3D helical dicyanamide complexes containing polyamine ligand

“…In the IR spectrum, both complexes show sharp bands in the 2306-2314 and 2151-2178 cm À1 ranges, which may be attributed to CBN stretching modes [10], and the 1361-1363 and 953-954 cm À1 bands are characteristic C-N stretching modes of the dicyanamide anions. Another 2847-3019 cm À1 band also suggests the existence of tmeda co-ligand.…”