RESUMO
Recently, Huo etâ al. has commented on our communication (Angew. Chem. Int. Ed. 2024, 63, e202317312, DOI: 10.1002/anie.202317312), regarding the multireference character (MRC) of our proposed cluster. Their argument is based on small HOMO-LUMO gap, fractional occupation density (FOD) and CASPT2(12,13) calculations. They also proposed that the singlet planar In4H+ cluster cannot be observed. We present our calculations which reveals that some of their arguments are based on wrong interpretation of data and inadequate use of methodology. While we certainly agree with the strong physical ground of FOD, CASSF and CASPT2 methodology, we believe that such analysis for clusters is not adequate.
RESUMO
Among the list of planar tetracoordinate atoms, the smallest element hydrogen is missing. No experimental and theoretical evidence have ever been put forwarded. Herein, we introduce the first planar tetracoordinate hydrogen atom (ptH) in the global minimum geometry of In4 H+ cluster. Bonding analysis indicates that the central hydrogen atom is acting like a proton and significant charge transfer from the surrounding In4 framework results in a negative charge of the central hydrogen atom. The proposed global minimum geometry possesses σ-aromaticity and the central hydrogen atom forms unusual multicentre bond with more than three centres.
RESUMO
Quadruple bonding in heavier main group elements is not known albeit having four valence orbitals accessible for bonding. Here we report the unprecedented quadruple bonding between a silicon atom and a transition metal fragment in the 1A1 electronic ground state of C3v symmetric SiRu(CO)3 based on high level theoretical calculations. Various bonding analyses reveal the nature of the Si[quadruple bond, length as m-dash]Ru quadruple bonding interaction, which involves one usual Si-Ru σ bond, two usual Si-Ru π bonds and one additional Si â Ru dative σ bond.
