ELECTROSPRAY MASS-SPECTROMETRY AND X-RAY CRYSTALLOGRAPHY STUDIES OF DIVALENT METAL-ION COMPLEXES OF TRIS(2-PYRIDYLMETHYL) AMINE

Coordination complexes of tris (2-pyridylmethyl) amine (TPA) were prep ared and characterized including [Zn(TPA)X]ClO4 (X=Cl, Br, I), [Cu(TPA )Br]ClO4, [Cd(TPA)Br-2], [Cd(TPA)(H2O)(NO3)]NO3, [Cd(TPA)I-2], [Co(TPA )Cl-2], [Fe(TPA)Cl-2] and [Mn(TPA)Cl-2]. The solid-state structures of Zn(TPA)ClClO4 (monoclinic space group, P2(1)/c; a = 14.733(3), b = 9. 408(2), c = 29.722(4) Angstrom, beta=90.65(1)degrees; V=4119(1) Angstr om(3); Z=8), Zn(TPA)IClO4 (triclinic space group, P (1) over bar; a=14 .435(3), b=17.069(4), c=9.745(2) Angstrom, alpha=100.36(2), beta=91.40 (2), gamma=114.62(1)degrees; V=2134(2) Angstrom(3); Z=4) and Cu(TPA)Br ClO4 (monoclinic space group, P2(1)/c; a=14.555(3), b=9.519(2), c=30.0 24(3) Angstrom, beta=91.66(1)degrees; V=4158(1) Angstrom(3); Z=8), con tain trigonal bipyramidal metal ions with halide coordinated in an api cal position. The X-ray structure of [Cd(TPA)(H2O)(NO3)]NO3 (monoclini c space group, P2(1)/n; a=15.415(4), b=9.333(2), c=17.429(4) Angstrom, beta=99.39(2)degrees; V=2474(2) Angstrom(3); Z=4) contains a seven-co ordinate cadmium ion including a bidentate nitrate anion and a water m olecule as ligands. The X-ray structure of [Cd(TPA)I-2] (monoclinic sp ace group, P2(1)/n; a=10.383(2), b=13.813(2), c=15.391(1) Angstrom, be ta=106.07(1)degrees; V=2121.1(5) Angstrom(3); Z=4) contains a cadmium ion with an approximately octahedral geometry. In this structure, the TPA ligand is conformationally distorted in order to accommodate the o ctahedral coordination geometry. The convenient new technique, electro spray mass spectrometry (ESI-MS), provided mass spectra consistent wit h X-ray and spectroscopic data. Mass analysis of solutions containing added competing anions was also consistent with solution data.