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From Neutral to Ionic Species: Syntheses and X‐ray Crystallographic and Multinuclear NMR Spectroscopic Studies of Li···P(SiMe 3 )–P t Bu 2 and Its Solvent Complexes
Author(s) -
Sattler Ewald,
Matern Eberhard,
Rothenberger Alexander,
Okrut Alexander,
Bombicz Petra,
Fernández Ignacio,
Kovács Ilona
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201301189
Subject(s) - chemistry , tetrahydrofuran , crystallography , conformational isomerism , ionic bonding , nuclear magnetic resonance spectroscopy , metalation , crystal structure , stereochemistry , tetramer , solvent , molecule , ion , organic chemistry , enzyme
Li(THF) 3 P(SiMe 3 )–P t Bu 2 ( 1 , THF = tetrahydrofuran) has been prepared by the reaction of (Me 3 Si) 2 P–P t Bu 2 with n ‐butyllithium in THF and isolated in good yields. Compound 1 eliminates THF in vacuo to yield the dimeric [Li(THF)P(SiMe 3 )–P t Bu 2 ] 2 ( 2 ). By metalation of H(SiMe 3 )P–P t Bu 2 with n ‐butyllithium in hexane, the solvent‐free derivative [Li(Me 3 Si)P–P t Bu 2 ] 4 ( 3 ) has been prepared. Compounds 1 – 3 form the ionic species [Li(TMEDA) 2 ] + [(Me 3 Si)P–P t Bu 2 ] – [ 4 , TMEDA = Me 2 N(CH 2 ) 2 NMe 2 ] and [Li(12‐crown‐4) 2 ] + [(SiMe 3 )P–P t Bu 2 ] – ( 5 ) with TMEDA and 12‐crown‐4, respectively, in solution. The molecular structures of 1 – 5 were established by single‐crystal X‐ray diffraction. Compound 3 forms a cyclic tetramer with a flat butterfly geometry. Extensive solution NMR spectroscopic investigations have shown that all species except for 3 exist in the same form in solution as in the solid state. Moreover, multinuclear variable‐temperature NMR studies showed that 2 is involved in a rapid conversion between conformers at 298 K, which can be slowed down on the NMR timescale at 183 K.