Borylene as an electron-pair donor for P … B pnicogen bonds
Ab initio MP2/aug’-cc-pVTZ calculations have been performed on the complexes (CO)2(HB):PXH2 and (N2)2(HB):PXH2, for X = F, Cl, NC, OH, CN, CCH, CH3, and H, in order to investigate the properties of these complexes which are stabilized by P … B pnicogen bonds, with B the electron-pair donor. The binding energies of these complexes exhibit an exponential dependence on the P-B distance, but they do not correlate with the MEP minima for (CO)2(HB) and (N2)2(HB), nor with the MEP maxima for PXH2. For fixed X, the binding energy of (N2)2(HB):PXH2 is greater than that of (CO)2(HB):PXH2. Charge-transfer stabilizes both series of complexes, and occurs from the B electron pair to the antibonding P-A σ orbital, with A the atom of X directly bonded to P. These charge-transfer energies also exhibit an exponential dependence on the P-B distance. In the complexes (CO)2(HB):PXH2, there is a second charge-transfer interaction from the lone pair on P to the antibonding π orbitals of the two C-O groups. Electron density analyses indicate that the P … B bonds in these complexes are stabilized by relatively weak interactions with little covalent character. The chemical shieldings of 11B are essentially unaffected by complex formation. In contrast, the shieldings of 31P increase from 10 to 50 ppm in the four most strongly bound complexes, but decrease by −4 to −12 ppm in the remaining complexes. For each series of complexes, EOM-CCSD spin-spin coupling constants 1pJ(P-B) increase quadratically with decreasing P-B distance. For fixed X, 1pJ(P-B) is greater for (CO)2(HB):PXH2 compared to (N2)2(HB):PXH2.
Publisher URL: https://link.springer.com/article/10.1007/s11224-017-0912-4
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.