Theoretical study of a series of alkyllithium clusters

Abstract The structural and energetic properties of a series of alkyllithium clusters (methyl, ethyl, n , iso-propyl, n , sec, tert-butyl) have been studied using density functional theory. Geometries and binding energies have been determined using the B3LYP functional and a polarised double zeta basis set. Geometries are found in good agreement with the available experimental data when the corresponding crystals are built from non-interacting clusters. The polyhedral hexameric clusters appear to be the most stable structures except for tert-butyllithium for which the polyhedral tetramer is favored. This behaviour is related to the high steric hindrance in the tert-butyllithium hexamers and the apolar character of their Li–alkyl bonds.

[1]  E. Weiss,et al.  Die kristall- und elektronenstruktur des methyllithiums , 1964 .

[2]  D. L. Cooper,et al.  Modern valence-bond description of (CH3)4Li4 , 1995 .

[3]  Dennis R. Salahub,et al.  Optimization of Gaussian-type basis sets for local spin density functional calculations. Part I. Boron through neon, optimization technique and validation , 1992 .

[4]  H. Lewis,et al.  Association of alkyllithium compounds in hydrocarbon media. Alkyllithium-base interactions , 1970 .

[5]  Max T. Rogers,et al.  The Preparation and Properties of Crystalline Lithium Alkyls , 1957 .

[6]  R. Lagow,et al.  Characterization of the vapor species of methyllithium by flash vaporization mass spectroscopy , 1984 .

[7]  H. Dietrich.  Die Kristallstruktur von Äthyl‐Lithium , 1963 .

[8]  B. Wakefield.  The Chemistry of Organolithium Compounds , 1974 .

[9]  D. Stalke,et al.  Structures of Classical Reagents in Chemical Synthesis: (nBuLi)6, (tBuLi)4, and the Metastable (tBuLi · Et2O)2 , 1993 .

[10]  Nicolaas J. R. van Eikema Hommes,et al.  The Carbon−Lithium Electron Pair Bond in (CH3Li)n (n = 1, 2, 4) , 1996 .

[11]  Michael L. McKee,et al.  Density Functional Calculations of Methyllithium, t-Butyllithium, and Phenyllithium Oligomers: Effect of Hyperconjugation on Conformation , 2001 .

[12]  D. Dixon,et al.  Electronic structure of the alkyllithium clusters, (CH3Li)n, n = 1-6, and (C2H5Li)n, n = 1-2 , 1980 .

[13]  H. Dietrich.  Low temperature study of the structure of crystalline ethyllithium , 1981 .

[14]  U. Siemeling,et al.  CRYSTAL STRUCTURE OF ISOPROPYLLITHIUM , 1994 .

[15]  D. Plavsic,et al.  Mass spectrometric investigations of alkyllithium compounds in the gas phase , 1986 .

[16]  E. Weiss,et al.  Über metall-alkyl-verbindungen: XII. verfeiner ung der kristallstruktur des methyllithiums , 1970 .

[17]  P. Schleyer,et al.  Lithium chemistry : a theoretical and experimental overview , 1995 .

[18]  A. Sapse,et al.  Ab initio studies of methyllithium clusters , 1982 .

[19]  Lucy M Ziurys,et al.  Synthesis of CH3K in the Gas Phase: Structural and Mechanistic Trends for Monomeric, Unsolvated CH3M and HCCM (M = Li, Na, K) , 2000 .

[20]  R. West,et al.  The Physical Properties and Structure of t-Butyllithium , 1962 .

[21]  R. Lagow,et al.  Synthesis of lithiomethanes (CH4−nLin) and characterization of the vapor species of lithiomethanes by flash vaporization mass spectroscopy , 1983 .

[22]  R. Parr.  Density-functional theory of atoms and molecules , 1989 .