Abstract

Structure and bonding analyses of the complexes [(PNP)Ir(NX)]+ (X=O, S, Se; PNP=N(CHCHPMe2)2) were investigated at the DFT, DFT-D3 and DFT-D3(BJ) levels using BP86, BLYP, PBE, revPBE and TPSS functionals. The Ir–NX bond in the thionitrosyl complex is longer than that in the nitrosyl and selenonitrosyl complexes, which is consistent with the observed trend for their experimental values. The Ir–NX bond has essentially IrNX double bond character, which supports the σ-donor and π-acceptor abilities of the [NX]+ ligands. The non-covalent P–NX distances decrease in the order DFT>DFT-D3>DFT-D3(BJ). The Ir–NX bond has a larger covalent character (85.7, 75.9 and 74.6%). Dispersion interactions between the metal and [NX]+ fragments are in the range 3.2–5.5kcal/mol (BP86), 3.2–5.4kcal/mol (BLYP), 1.9–3.1kcal/mol (PBE), 3.5–5.5kcal/mol (revPBE) and 2.6–3.8kcal/mol (TPSS), which are smaller than the corresponding DFT-D3(BJ) dispersion corrections 4.9–8.6kcal/mol (BP86), 5.2–7.9kcal/mol (BLYP), 2.7–4.0kcal/mol (PBE), 5.3–7.6kcal/mol (revPBE) and 2.7–5.2kcal/mol (TPSS). The dispersion corrected DFT (DFT-D3 and DFT-D3(BJ)) methods provide quite an accurate estimate of the dispersion energy, which can be judged by the observation that the experimental and optimized Ir–NX bond distances are consistent with the most accurate dispersion corrected DFT-D3(BJ) bond dissociation energy of Ir–NX bonds.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.