The role of the 5f orbitals in bonding, aromaticity, and reactivity of planar lsocyclic and heterocyclic uranium clusters
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Ημερομηνία
Συγγραφείς
Tsipis, A. C.
Kefalidis, C. E.
Tsipis, C. A.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Am Chem Soc
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Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The molecular and electronic structures, stabilities, bonding features and magnetic properties of prototypical planar isocyclic cyclo-U(n)X(n) (n = 3, 4; X = O, NH) and heterocyclic cyclo-U(n)(mu(2)-X)(n) (n = 3, 4; X = C, CH, NH) clusters as well as the E@[c-U(4)(mu(2)-C)(4)], (E = H(+), C, Si, Ge) and U@[c-U(5)(mu(2)-C)(5)] molecules including a planar tetracoordinate element E (ptE) and pentacoordinate U (ppU) at the ring centers, respectively, have been thoroughly investigated by means of electronic structure calculation methods at the DFT level. It was shown that 5f orbitals play a key role in the bonding of these f-block metal systems significantly contributing to the cyclic electron delocalization and the associated magnetic diatropic (magnetic aromaticity) response. The aromaticity of the perfectly planar cyclo-U(n)X(n) (n = 3, 4; X = O, NH), cyclo-U(n) (mu(2)-X)(n) (n = 3, 4; X = C, CH, NH), E @ [c-U(4)(mu(2)-C)(4)], (E = H(+), C, Si, Ge) and U @ [c-U(5)(mu(2)-C)(5)] clusters was verified by an efficient and simple criterion in probing the aromaticity/antiaromaticity of a molecule, that of the nucleus-independent chemical shift, NICS(0), NICS(1), NICS(zz)(0) and the most refined NICS(zz)(1) index in conjunction with the NICS scan profiles. Natural bond orbital analyses provided a clear picture of the bonding pattern in the planar isocyclic and heterocyclic uranium clusters and revealed the features that stabilize the ptE's inside the six- and eight-member uranacycle rings. The ptE's benefit from a considerable electron transfer from the surrounding uranium atoms in the E@[c-U(4)(mu(2)-C)(4)], (E = H(+), C, Si, Ge) and U@[c-U(5)(mu(2)-C)(5)]clusters justifying the high occupancy of the np orbitals of the central atom E.
Περιγραφή
Λέξεις-κλειδιά
density-functional calculations, electron-transfer reactions, chemical-shifts nics, tetracoordinate carbon, actinide complexes, infrared-spectra, solid neon, theoretical investigations, relativistic dft, cuo(ng)(n) ng
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000257507400047
http://pubs.acs.org/doi/pdfplus/10.1021/ja802344z
http://pubs.acs.org/doi/pdfplus/10.1021/ja802344z
Γλώσσα
en
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Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας