Effect of temperature, counter-ion, and solvent on the absorption spectrum of the 4,5-methylenephenanthrene anion

Abstract

Minus Seventy ' thermostat bath was used for temperatures below $10" and a Tomnson and Mercer Bridge Controlled thermostat bath for temperatures above + 10".The temperature of the cell, measured by a copperconstantan thermocouple, remained constant to & 0.2' over the range of temperatures studied.Conductivity Measuremelzts.--X Wayne-Kerr universal bridge B221 was used for the conductivity measurements.

Magnetic resonance. X. Spectroscopy of carbanions and the effect of ion pairing on chemical shifts

“…(5) The values obtained for AH and AS are similar to those found for several other closely related systems. 5,29,33,36 Interpretation of Thermodynamic Results. The values of the energy terms associated with the conversion of contact into solvent-separated ion pairs have been interpreted by several workers.4-7 The major features of the theory will be briefly mentioned here so that the values in Table V can be put in perspective.…”

The solvation of diphenylmethyl carbanions using variable temperature carbon-13 magnetic resonance

“…We have observed the EPR spectrum of the metastable triplet of [7]I (T71). The average distance between the two unpaired electrons is found to be substantially greater than that observed in triplet benzene or p-dialkylbenzenes.…”

“…29 It is especially important to emphasize the danger of comparing chemical shifts of lithium salts to those of the other alkali metals because, even when the shifts are very close, the state of solvation may be significantly different. Electron Paramagnetic Resonance of Metastable [7]Paracyclophane: Out-of-Plane Distortions of a Triplet Benzene Sir:…”

“…The recent syntheses of the [7]and [6]paracyclophanes (I) have made available compounds in which a single benzene ring experiences substantial out-of-plane distortions.1"3 Unlike the previously prepared [m,m]paracyclophanes (II), the nonplanar 7r-electron systems are not complicated by inter-ring interactions.4…”