μ-BENZENE-1,2,4,5-TETRACARBOXYLATO-κ²O¹:O4)BIS[ AQUABIS- 2-(AMINOMETHYL) PYRIDINE-μ²N,N') NICKEL (II)] DECAHYDRATE: STRUCTURE AND MAGNETIC PROPERTIES.

μ-Benzene-1,2,4,5-tetracarboxylato-&@954;²O¹:O⁴)bis[ aquabis- 2-(aminomethyl) pyridine-κ²N,N') nickel (II)] decahydrate, [Ni₂(amp)₄(btc)(H₂O)₂].10H₂O has been synthesized and its crystal structure determined by X-ray diffraction. The complex crystallizes in the Monoclinic space group P21/n with cell dimensions a= 11.0102 (10) Å, b= 21.5416 (19) Å, c= 11.0445 (10) Å and β= 118.753 (1)°, and two formula units per cell (Z= 2, Z'= 0.5). The structure consists of centrosymmetric dimeric units in which the benzene tetracarboxylate anions (btc) bridge the symmetry-related nickel (II) cations, two bidentate chelating molecules of 2-(aminomethyl) pyridine and a terminal aqua ligand completing the six-fold coordination at each metal. These dimers link to each other via H-bonding to form chains parallel to [100], while the water solvates form a strongly bound 2D network parallel to (100), made up by small (R⁴ ₄(8)) and large (R^{20 20}(40)) rings, the latter ones "pierced" by the chains of dimmers, with a profuse H-bonding interconnection between both substructures. Magnetic susceptibility measurements as a function of temperature disclose weak interdimeric exchange interactions. Fitting of these data to a dimeric model yields J= -3.5 cm^-1 and g= 2.13. [ABSTRACT FROM AUTHOR]