Elemental analysis for carbon, nitrogen and hydrogen were carried out on a FLASH 2000 Organic Elemental Analyzer, CHNS-O analyser by Thermo Scientific. Thermo Scientific iCAP 6000 SERIES duo ICAP Spectrometer was used to determine the metal content. Thermogravimetric analysis was investigated using a Mettler Toledo TGA/DSC1 STAR System; Infrared spectra were recorded on a Perkin-Elmer model IR-457 spectrometer and a spectrum 100 FT-IR Perkin Perkin-Elmer spectrometer, while the UV/Vis spectrum was recorded using an Agilent HP8453 Diode Array UV/Vis Spectrometer. The magnetic susceptibility measurement was made using the Sherwood Scientific magnetic susceptibility balance; while X-ray diffraction was carried using a Bruker APEX diffractometer.

N-(2-pyridylmethyl)-(L)-alanine) (L)(0.361 g, 2 mmol) in 10 mL aqueous ethanol was added drop wise to a 5 ml aqueous solution of Co(OOCH₃)₂∙H₂O (0.249 g, 1 mmol,) while stirring at room temperature. After stirring for a further 10 minutes,

Scheme 1. Synthesis and structure of N-(2-pyridylmethyl)-L-alanine) isothiocyanate Cobalt(III).

NH₄SCN, (0.16 g, 2 mmol,) in 2 mL distilled water was added drop wise and stirring continued for a further two hours. Rectangular reddish brown crystals suitable for X-ray analysis were obtained from the solution by slow evaporation. Yield: 81%; anal. Calc. (Found) for C₁₉H₂₂N₅O₄SCo; C:48.00 (47.92); H:4.66 (4.78); N: 14.73 (14.72); S: 6.74 (6.69); Co: 12.40 (12.28). The synthesis of N-(2-pyridylmethyl)-L-alanine) isothiocyanate Cobalt(III) is summarized in Scheme 1.

A suitable single crystal of the title compound was mounted on a glass fiber on the goniometer head of a Bruker APEX diffractometer and data were collected using graphite monochromated Cu-K_α radiation (λ = 1.54178 Å, operating at 50 kV and 40 mA) at a temperature of 100 K. Crystal data, data collection and structure refinement details are summarized in Table 1.

The structure was solved by direct methods and refined by full-matrix least squares on F² [12] . All non-Hydrogen atoms were refined anisotropically. Hydrogen atoms were included in calculated positions, assigned isotropic thermal parameters and allowed to ride on their parent carbon atoms. All calculations were carried out using the SHELXTL package [13] . CCDC 1419814 contains the supplementary crystallographic data for this paper.

In the IR spectrum of the Co(III) complex, a very strong infrared absorption band at 1609 cm⁻¹ is attributed to υ_C=C and υ_C=N of the pyridyl ring, while the strong band at 2098 cm⁻¹ suggest the presence of N=C=S stretch [14] [15] [16] , as confirmed by the single crystal structure of the compound. Two distinct peaks at 362 nm and 497 nm are observed in the UV-Visible spectrum of the complex and attributed to spin allowed d-d transitions.

The thermal behaviour of the title compound (Figure 1), recorded under an N₂ atmosphere, in the temperature range of 25˚C to 600˚C at a heating rate of 25˚C min⁻¹ shows a one-step decomposition patterns at 310˚C though with a small shoulder at 240˚C which probably accounts for the decomposition of the

organic ligands [calc. 75.2% (found 75.8%)]. The final residue of [24.15% (calc. 24.61%)) represents a mixture of Cobalt oxides, CoO and Co₂O₃.

The peak at m/z = 474.1 corresponds to C₁₉H₂₂N₅O₄SCo (calc. 475.41) which confirms the molecular weight of the compound. The effective magnetic moment, μ_eff was found to be consistent with a d⁶ low-spin configuration with some degree of spin-orbit coupling.

The structure of the title compound (I) is represented in Scheme 1 and comprise the [Co(L)₂]⁺ cation and the NCS⁻ anion with the resulting complex having the composition [Co(L)₂]⁺NCS⁻. The two L ligands are bonded to the cobalt centre via their two pyridyl nitrogen atoms (Co(1)-N(1), 1.931(3) Å; Co(1)-N(3), 1.929(3) Å), two secondary amine nitrogen atoms (Co(1)-N(2), 1.971(4)Å; Co(1)-N(4), 1.967(3) Å) and two carboxylate oxygen atoms (Co(1)-O(2), 1.884(3) Å; Co(1)-O(4), 1.891(3) Å) to give a pseudo octahedral geometry around the cobalt atom (Figure 2 and Table 2). The X-ray crystal structure reveals that the thiocyanate anion in the crystal lattice is not bonded to the Co(III) centre but forms interionic hydrogen bonds [17] [18] , through the nitrogen atom of the NCS⁻ anion, [N(4)-H(4A)...N(5)#1 (Figure 3, Table 3)]. A second intermolecular hydrogen bond, [N(2)-H(2A)...O(3)#2 (Table 3)] is observed linking two different monomeric centres. The crystallographic indicators show a good-quality data set [R(int) = 0.0497 and R1(all data) = 0.0539]. Comparable bonds lengths and bond angles are observed. The average Co-N bond length (1.950 Å) is longer than the average Co-O bond length (1.886 Å) as expected, and these values are in good agreement with those of similar cobalt(III) complexes [19] . The trans bond angles around the cobalt center, [N(3)-Co(1)-N(1) (174.18(16)˚), O(2)-Co(1)-N(4) (171.62(16)˚), O(4)-Co(1)-N(2) (172.66(16)˚)] deviates slightly from the theoretical value of 180˚, some of the cis bond angles deviated considerably from the theoretical value of 90˚ [N(1)-Co(1)-N(2) bond angle of 94.30(18)˚ [19] ]. The bond angle of the N-C-S thiocyanate anion is within the expected range of 178˚ - 182˚ [18] . The packing diagramme of the title compound is shown in Figure 4.

Symmetry transformations used to generate equivalent atoms: #1 x − 1, y, z #2 x, y − 1, z.