STRUCTURE OF [1.1]FERROCENOPHANYLLITHIUM IN THE SOLUTION AND THE SOLID-STATE - ABSENCE OF AN INTRAMOLECULAR [C-H-C](-) HYDROGEN-BOND

[1.1]Ferrocenophanyllithium (1) is shown by dynamic NMR (DNMR) and iso topic perturbation to undergo a rapid intramolecular 1,12-proton trans fer coupled with 1,12-lithium ion transfer. The first [C-H-C](-) hydro gen bond previously reported to be present in 1 is shown by X-ray crys tallography to be absent in the solid state. The C-13 NMR spectrum of the bridge-labeled compound [1,12-C-13(2)][1.1]ferrocenophanyl[1-Li-6] lithium (6) in 2,5-dimethyltetrahydrofuran (DMTHF) displays a 1:1:1 tr iplet ((1)J(C-13, Li-6) = 4.0 Hz) showing that Li-6 is bonded to C-1 a nd that 1 is monomeric. Transient nuclear Overhauser effects (tNOE's) measured in DEE-d(10) in bridged monodeuterated 1 show that the bridge s in 1 are syn and not anti to each other and that lithium is exo-coor dinated to the anionic bridge carbon. The (1)J(C-13, H-1) coupling con stants show that the hybridization of the carbanionic carbon is interm ediate between sp(2) and sp(3). Thus the solution and solid state stru ctures of 1 are similar. UV-vis spectroscopy shows that 1 exists mainl y as contact ion pairs (CLPs) in the temperature range -100 to +25 deg rees C in THF, DMTHF, and diethyl ether (DEE). In dimethoxyethane (DME ), 1 is mainly CIPs above +25 degrees C but is mainly separated ion pa irs (SIPs) below -30 degrees C.