Department of Chemistry, National University of Singapore3 Science Drive 3, 117543 Singapore.
Inorg Chem. 2020 Sep 8;59(17):12486-12493. doi: 10.1021/acs.inorgchem.0c01585. Epub 2020 Aug 11.
Pyridinylidene-amides (PYAs) are a relatively new type of N-donor ligands that can exist in three isomeric forms and adopt various resonance structures. This makes them electronically flexible, and in order to evaluate their electronic profile using the Huynh electronic parameter (HEP), seven structurally diverse mixed -heterocyclic carbenes (NHCs)/PYA palladium complexes of the type -[PdBr(Pr-bimy)(PYA)] were prepared and fully characterized by various spectroscopic and spectrometric methods. This study shows that PYAs are among the strongest, formally neutral N-donors, but they are still weaker than phosphines and organometallic ligands such as NHCs. Notably, the donating abilities of isomeric PYAs are distinct and can be further fine-tuned by the choice of two substituents making them structurally and electronically versatile. These characteristics and the ease of their preparation hold promise for a wide applicability in coordination chemistry.
吡啶基甲酰胺（PYAs）是一种相对较新的 N 供体配体，它可以以三种异构形式存在并采用各种共振结构。这使得它们在电子上具有灵活性，为了使用 Huynh 电子参数（HEP）评估它们的电子特性，我们制备了七种结构多样的混合杂环卡宾（NHC）/PYA 钯配合物，类型为-[PdBr(Pr-bimy)(PYA)]，并通过各种光谱和光谱方法进行了充分的表征。本研究表明，PYAs 是最强的、形式上中性的 N 供体之一，但它们仍然比膦和有机金属配体（如 NHC）弱。值得注意的是，异构 PYAs 的供电子能力是不同的，可以通过选择两个取代基进一步微调，使它们在结构和电子上具有多功能性。这些特性以及它们的制备的便利性为在配位化学中的广泛应用提供了希望。
