Syntheses and coordination isomerism of heteroleptic divalent-metal (M = Co, Zn) carbazate complexes

<div><p>Three heteroleptic divalent-metal alkyl-carbazate-thiocyanate complexes, [M(NCS)<sub>2</sub>(NH<sub>2</sub>NHCOOR)<sub>2</sub>] [M = Co and R = CH<sub>2</sub>CH<sub>3</sub> (<b>1</b>); M = Co and R = CH<sub>3</sub> (<b>2</b>); M = Zn and R = CH<sub>3</sub> (<b>3</b>)], have been prepared and characterized, and their crystal structures determined. In <b>1</b>, Co(II) adopts a fairly regular centrosymmetric <i>trans</i>-CoO<sub>2</sub>N<sub>4</sub> octahedral geometry arising from its coordination by two N,O-bidentate ethylcarbazate ligands and two <i>trans</i> N-bonded thiocyanates. In isostructural <b>2</b> and <b>3</b>, the metals adopt distorted <i>cis</i>-MO<sub>2</sub>N<sub>4</sub> octahedral geometries arising from two N,O-bidentate methylcarbazate ligands with <i>cis</i> N-bonded thiocyanates. The crystal structures feature N–H⋯O and N–H⋯S interactions. Thermal analysis data show that these compounds begin to decompose at temperatures between 130 and 160 °C. Crystal data: <b>1</b>, CoC<sub>8</sub>H<sub>16</sub>N<sub>6</sub>O<sub>4</sub>S<sub>2</sub>, <i>M</i><sub>r</sub> = 383.32, <i>P2</i><sub><i>1</i></sub><i>/n</i> (No. 14), <i>a</i> = 5.2599(3) Å, <i>b</i> = 7.4209(4) Å, <i>c</i> = 20.1948(12) Å, <i>β</i> = 94.070(1)°, <i>V</i> = 786.28(8) Å<sup>3</sup>, <i>Z</i> = 2, <i>R</i>(<i>F</i>) = 0.028, <i>wR</i>(<i>F</i><sup>2</sup>) = 0.073; <b>2</b>, CoC<sub>6</sub>H<sub>12</sub>N<sub>6</sub>O<sub>4</sub>S<sub>2</sub>, <i>M</i><sub>r</sub> = 355.27, <i>P2</i><sub><i>1</i></sub><i>/n</i> (No. 14), <i>a</i> = 7.8663(3) Å, <i>b</i> = 10.5804(3) Å, <i>c</i> = 17.6313(5) Å, <i>β</i> = 102.019(10)°, <i>V</i> = 1435.26(8) Å<sup>3</sup>, <i>Z</i> = 4, <i>R</i>(<i>F</i>) = 0.036, <i>wR</i>(<i>F</i><sup>2</sup>) = 0.097; <b>3</b>, ZnC<sub>6</sub>H<sub>12</sub>N<sub>6</sub>O<sub>4</sub>S<sub>2</sub>, <i>M</i><sub>r</sub> = 361.71, <i>P2</i><sub><i>1</i></sub><i>/n</i> (No. 14), <i>a</i> = 7.8883(2) Å, <i>b</i> = 10.5756(3) Å, <i>c</i> = 17.5827(5) Å, <i>β</i> = 101.676(1)°, <i>V</i> = 1436.46(7) Å<sup>3</sup>, <i>Z</i> = 4, <i>R</i>(<i>F</i>) = 0.031, <i>wR</i>(<i>F</i><sup>2</sup>) = 0.084.</p></div>