Darmstadtium, roentgenium, and copernicium form strong bonds with cyanide

Abstract

We report the structures and properties of the cyanide complexes of three superheavy elements (darmstadtium, roentgenium, and copernicium) studied using two-and four-component relativistic methodologies. The electronic and structural properties of these complexes are compared to the corresponding complexes of platinum, gold, and mercury. The results indicate that these superheavy elements form strong bonds with cyanide. Moreover, the calculated absorption spectra of these superheavy-element cyanides show similar trends to those of the corresponding heavyatom cyanides. The calculated vibrational frequencies of the heavy-metal cyanides are in good agreement with available experimental results lending support to the quality of our calculated vibrational frequencies for the superheavy-atom cyanides.copernicium, darmstadtium, relativistic DFT, roentgenium, superheavy elements | I N TR ODU C TI ONThe term heavy atom refers roughly to elements in the fourth to sixth periods of the periodic table, whereas elements in the seventh period are called superheavy elements. Heavy-element compounds have been rather extensively studied [1][2][3][4][5][6][7] compared to the superheavy ones. This is due to the abundance of the heavy elements and the many uses of heavy-element compounds; for instance, gold dicyanide (AuðCNÞ 2 2 ) was used in gold mining, [8,9] platinum cyanides are used in nanomaterials, [10] whereas mercury(II) cyanide (HgðCNÞ 2 ) was used as an antiseptic [11] until this was stopped due to its toxicity. [12] In contrast, the lack of a natural abundance of the superheavy elements has limited the number of studies of compounds involving these superheavy elements. In particular, with the exception of RgCN, [6] there has been no studies of the cyanide complexes of Ds, Rg, and Cn reported previously in the literature. Patzschke and Pyykk€ o [13] studied the properties of darmstadtium carbonyl and carbide and compared them to platinum carbide and carbonyl and found that darmstadtium resembled platinum in its bonding properties. [13] Theoretical studies of darmstadtium hexafluoride (DsF 6 ) and darmstadtium tetrachloride (DsCl 4 ) have also been reported and these compounds have been shown to have properties similar to those of the lighter group analogues. [14][15][16] The structure and bonding properties of roentgenium monocyanide have been compared with the cyanides of copper, silver, and gold. [6] Theoretical studies on the electronic structures of RgX (X 5 H, F, Cl, Br, O, Au, or Rg) have also been reported [5] where the RgAH bond in RgH was found to be strong due to relativistic effects, 153.0 pm using ZORA and 150.3 pm using spin-orbit pseudopotential coupled cluster calculations, in contrast to 190.8 pm using nonrelativistic calculations (a 27% relativistic bond-length contraction). Calculations using two-component spin-orbit-coupled relativistic energy-adjusted pseudopotentials showed that the CnAH bond length in CnH 1 is shorter than the ZnAH bond length in ZnH 1 . [17] The calculated equilibrium bond d...

The Chemical Bond and s–d Hybridization in Coinage Metal(I) Cyanides

“…A qualitative bonding analysis by Pyykkö et al, based on on the inspection of the molecular orbitals and in consideration of the short M–C bond distance (just few pm longer than those predicted for triple-bond covalent radii), suggested a multiple character of the Au–C bond. A similar conclusion has been drawn by Ruud et al in the case of AuCN. In photoelectron imaging experiments, Fan et al found that the electron affinities of CuCN and AgCN are larger than those of the metal atoms, while that for AuCN is smaller.…”

“…Photoelectron experiments on Au­(CN) 2 – , by comparison with its lighter congeners, Ag­(CN) 2 – and Cu­(CN) 2 – , hint at a significant covalent character of the Au–C bond. , The atomic-like transitions in Cu­(CN) 2 – are indeed consistent with a more ionic bond nature, whereas the bond in Ag­(CN) 2 – is expected to be of intermediate character. The authors point out that the high stability of Au­(CN) 2 – is consistent with the covalent character of the bond and surmise that s–d hybridization enhances gold ability to form multiple bonds, which would explain the short Au–C bond distance in this system. , A number of high-precision calculations already exist for the cyanides of noble metals (see refs and and references therein). Frenking et al investigated the metal–C bonds in cyanides and isocyanides of coinage metals ([M­(CN) 2 – ], with M = Cu, Ag, and Au), analyzing the chemical bond in terms of a well-defined energy partition scheme.…”

New Understanding on an Old Compound: Insights on the Origin of Chain Sequence Defects and Their Impact on the Electronic Structure of AuCN

“…These multiple features of the AuÀ C bond in AuCN have been suggested in previous works. [27,28] It is very striking to realize that the so-called defects in the N�CÀ AuÀ C�N sequences increase their range order while the "ordered" C�NÀ AuÀ C�N sequences lose order by the grinding process. To understand this point, as well as to explain the observed transformations of the high-resolution C1s spectrum, it is necessary to elucidate the probable origin of the N�CÀ AuÀ C�N defects.…”

Static dipole polarizability of palladium from relativistic coupled-cluster theory

“…Palladium is a rare element that is used in many applications such as catalytic converters and fuel cell technologies. The valence ground state electron configuration of atomic palladium is closed-shell 4d 10 5s 0 , differing from all the other Group 10 members Ni (3d 8 5s 2 ), Pt (5d 9 6s 1 ), and Ds (6d 8 7s 2 ), which are open-shell [14,15]. In fact, Pd is the only known atom in its ground electronic state * paul.jerabek@gmail.com † p.a.schwerdtfeger@massey.ac.nz ‡ jnagle@bowdoin.edu not to have at least one electron in an outer-shell ns or np orbital [16].…”