Abstract
The structure and valence isomerizations of perdehydrotetrasilacyclobutadiene (Si4) are discussed on the basis of concepts of cyclic π− and σ−conjugation. Calculations by the MINDO/3 and MNDO methods established two types of geometric configurations with D4h symmetry for both the singlet and triplet states of perdehydrotetrasilacyclobutadiene, differing in inversion of the HOMO and LUMO. Neither D4h configuration of the singlet state corresponds to minima on the potential energy surface, and these configurations are distorted, one toward a rectangular structure with D2h symmetry with alternation of bond lengths in the ring, and the other toward a rhombic bicyclic structure with D2h symmetry. The latter structure corresponds to the global minimum on the potential energy surface of the Si4.
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Literature cited
A. Liberles, “Delocalization,” J. Chem. Educ., 54, No. 8, 479–484 (1977).
C. Sandorfy, “LCAO MO calculations of saturated hydrocarbons and their substituted derivatives,” Can. J. Chem., 33, No. 8, 1337–1351 (1955).
J. A. Pople and D. P. Santry, “A molecular orbital theory of hydrocarbons. 1. Bond delocalization in paraffins,” Mol. Phys., 7, No. 3, 269–286 (1964).
M. J. S. Dewar and M. L. McKee, “Aspects of cyclic conjugation,” Pure Appl. Chem., 52, No. 6, 1431–1441 (1980).
M. J. S. Dewar, “Chemical implications of σ-conjugation,” J. Am. Chem. Soc., 106, No. 3, 669–682 (1984).
V. I. Minkin and R. M. Minyaev, Nonclassical Structures of Organic Compounds [in Russian], Izd. Rostov Univ., Rostov-on-Don (1985).
R. B. King, The Bonding Topology of Polyhedral Molecules; Chemical Applications of Topology and Graph Theory, Elsevier, Amsterdam (1983).
M. N. Glukhovtsev, B. Ya. Simkin, and V. I. Minkin, “π-System of cyclic conjugation — a new factor in stabilization of molecular structure,” Summaries of Papers from 9th All-Union Conference on Quantum Chemistry, Ivanovo, June 10–12, 1985; Chernogolovka (1985), pp. 31–32.
V. I. Minkin, M. N. Glukhovtsev, and B. Ya. Simkin, “σ-Aromaticity and σ-antiaromaticity,” Zh. Org. Chim., 23, No. 10 (1987).
R. A. Whiteside, R. Krishman, M. J. Frisch, et al., “Cyclic C3 structures,” Chem. Phys. Lett., 80, No. 3, 547–551 (1980).
R. O. Jones, “Energy surfaces for Si3 and C3: a comparative study,” Phys. Rev. A, 32, No. 5, 2589–2594 (1985).
R. S. Grev and H. F. Schaefer, “The ground state of Si3. Two near-degenerate isomers,” Chem. Phys. Lett., 119, No. 2, 111–118 (1985).
A. F. Cuthbertson and C. Glidewell, “MINDO/3 study of some tetraatomic clusters,” Inorg. Chim. Acta, 49, No. 1, 91–97 (1981).
W. S. Verwoerd, “MNDO calculations of silicon-containing molecules,” J. Comput. Chem., 3, No. 3, 445–450 (1982).
B. N. Plakhutin and G. M. Zhidomirov, “Construction of symmetry rule for terms of non-Roothaan type in restricted Hartree-Fock method,” Zh. Strukt. Khim., 27, No. 2, 3–8 (1986).
H. Kollmar and V. Staemmler, “Violation of Hund's rule by spin polarization in molecules,” Theor. Chim. Acta, 48, No. 3, 233–239 (1978).
M. N. Glukhovtsev, B. Ya. Simkin, and V. I. Minkin, “Structure and valence isomerizations of antiaromatic molecules,” Usp. Khim., 54, No. 1, 86–125 (1985).
M. N. Glukhovtsev, B. R. Simkin, and V. I. Minkin, “Structure and valence isomerizations of antiaromatic molecules. 9. Aromaticity and antiaromaticity in orthogonal systems of cyclic conjugations: cyclobutadiyne and cyclohexatriyne,” Zh. Org. Khim., 22, No. 1, 3–19 (1986).
K. Lammerstsma, J. A. Pople, and P. R. Schleyer, “Structures and energies of C4H2 2+,” J. Am. Chem. Soc., 108, No. 1, 7–10 (1986).
M. J. S. Dewar, D. H. Lo, and C. A. Ramsden, “Ground states of molecules. 29. MINDO/3 calculations of compounds containing third-row elements,” J. Am. Chem. Soc., 97, No. 6, 1311–1318 (1975).
M. J. S. Dewar, R. C. Haddon, W. K. Li, et al., “Ground states of molecules. 31. MINDO/3 study of CH2, NH2 +, and O2,” J. Am. Chem. Soc., 97, No. 16, 4540–4545 (1975).
G. W. Trucks and R. J. Bartlett, “Isomers of Si2C2: an MBPT study,” J. Mol. Struct. Theor. Chem., 135, No. 3, 423–428 (1986).
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Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 4, pp. 414–420, July–August, 1987.
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Glukhovtsev, M.N., Simkin, B.Y., Minkin, V.I. et al. Quantum-chemical investigation of structure and valence isomerizations of perdehydrotetrasilacyclobutadiene. Theor Exp Chem 23, 387–393 (1988). https://doi.org/10.1007/BF00536355
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DOI: https://doi.org/10.1007/BF00536355