Synthesis of Pt(dpk)Cl4 and the Reversible Hydration to Pt(dpk-O-OH)Cl3·H-phenCl: X-ray, Spectroscopic, and Electrochemical Characterization

We report on the synthesis of a platinum(IV) compound containing a di-2-pyridyl ketone (dpk) ligand that is stable
both in its anhydrous form [Pt(dpk)Cl4] (1) and in its hydrated form [Pt(dpk-O-OH)Cl3]·H-phenCl (2). The crystal
structure of the hydrated form shows that one of the hydroxide groups from the resulting gem-diol has undergone
a cyclometalation/condensation reaction resulting in an oxygen atom directly coordinated to the Pt(IV) center and
the formation of H-phenCl. We correlate our physical data with predictions made by molecular modeling, and we
propose an explanation for the unusual activity found for this dpk ketone. Spectroscopic and solubility studies are
presented here, as well. Electrochemical studies of 1 indicate that it undergoes a highly irreversible reduction at
a potential of about −0.45 V vs Ag+/Ag in CH3CN and that the irreversibility is likely due to an EC mechanism, the
nature of which is currently under further investigation. Another distinct redox pair, apparently reversible, appears
at a potential of about −1.1 V vs Ag+/Ag.

本报告详述了一种含二(2-吡啶基)酮(dpk)配体的铂(IV)化合物的合成。该化合物在无水形式[Pt(dpk)Cl4](1)和含水形式[Pt(dpk-O-OH)Cl3]·H-phenCl(2)中均表现出稳定性。含水形式的晶体结构揭示，由Gem-二醇产生的羟基之一经历了环金属化/缩合反应，导致氧原子直接配位于铂(IV)中心，并形成了H-phenCl。我们将我们的物理数据与分子建模的预测进行关联，并对该dpk酮的不寻常活性提出了合理解释。此外，还展示了光谱学和溶解度研究。对1的电解化学研究表明，它在约-0.45 V vs Ag+/Ag的电位下在CH3CN中经历了一种高度不可逆的还原反应，而这种不可逆性可能是由EC机制引起的，其本质目前正在进一步研究中。另一个明显的氧化还原对，似乎具有可逆性，出现在约-1.1 V vs Ag+/Ag的电位下。