Observation of Intramolecular Paramagnetic <i>T</i><sub>1</sub> Spin Decoupling in the <sup>13</sup>C NMR Spectra of Triazacyclohexane Complexes of Ni(II)

<i>N</i>-Benzyl-substituted complexes [(triazacyclohexane)Ni(NCMe)<sub>3</sub>](BF<sub>4</sub>)<sub>2</sub> and their diamagnetic zinc analogues have been prepared and characterized by X-ray crystallography. The <i>T</i><sub>1</sub> spin decoupling observed in their paramagnetic <sup>13</sup>C NMR spectra can be quantitatively described by newly derived expressions that allow an independent determination of <i>T</i><sub>2</sub> of the <sup>13</sup>C signal, <i>T</i><sub>1</sub> of the attached H or F, and the <sup>1</sup><i>J</i> coupling constant by line shape analysis.