Statistical treatment of recordings of spontaneous unit discharges from the ventromedial nucleus and the lateral area of the hypothalamus (the activities in one area being recorded while the other was stimulated) revealed significant reciprocal relations. The concept that glucose-sensitive neurons are present in the ventromedial nucleus was supported by the effects on the spontaneous unit discharges of injecting glucose and other-solutions intravenously.

The two-color (1+1′) threshold photoelectron spectra of naphthalene in a supersonic free jet have been recorded via nine vibronic levels of the S1 electronic state up to about 1420 cm−1 above the S1 band origin. The threshold photoelectron spectra recorded via the S1 band origin and via totally symmetric ag vibronic levels show significant intensity in Δν=+1 transitions in nontotally symmetric vibrations having b1g symmetry indicating that the ionization transition gains significant intensity through a vibronic coupling mechanism between the two lowest doublet cationic states. The strongest departure from the expected Δν=0 propensity in the threshold photoelectron spectra occurs through excitation of the totally symmetric 8 mode having ag symmetry indicating that a considerable displacement occurs along the normal coordinate of this 8 mode upon ionization from the S1 state. The superior resolution of the threshold photoelectron technique over conventional photoelectron methods has allowed accurate values for the fundamental vibrational frequencies of naphthalene in its ground cationic state to be determined and it has also allowed a more rigorous investigation of the vibronic coupling mechanism that occurs between the two lowest doublet cationic states. Moreover, an improved value for the adiabatic ionization energy of naphthalene of 65 687±7 cm−1 (8.1442±0.0009 eV) has been determined.

The vacuum ultra-violet spectra of various mono-substituted benz~les were measured in the wavelength region of 1550 3, to 2200 A in the vapour phase by a recording vacuum ultra-violet spectrophotometer. The compounds studied here are phenols (phenol, anisole, phenetole and thiophenol), halogenobenzenes (fluorobenzene, chlorobenzene, bromobenzene and iodobenzene), and toluene. It was found that four ~ ~r ~ -transition bands appear in the wavelength region of 1550 3, to 3000 ~, for phenol, anisole, phenetole, fluorobenzene, chlorobenzene and bromobenzene, On the other hand, six ~r~ ~ ~ transition bands were found in the same wavelength region for thiophenol and iodobenzene. The absorption spectra of the former group are similar to that of benzene itself. On the other hand, the absorption spectra of the latter group are very different from that of benzene and rather similar to those of the anilines studied in a previous paper. From this point of view, the former group may be regarded as the molecules with weak substituents, and the latter as the molecules with strong substituents.Theoretical studies of rr-electron structures have been carried out with the phenols and halogenobenzenes by considering configurational interactions among the ground, locally excited, and intramolecular charge-transfer configurations. Good agreement was obtained between the experimental and theoretical values for both transition energies and oscillator strengths. It was concluded that the energies of charge-transfer configurations have a great effect upon the absorption spectra of the mono-substituted benzene molecules. That is to say, the charge-transfer configurations lie intermediate between the locally excited configurations for the molecules with strong substituents, while for the molecules with weak substituents they have higher energies than the locally excited configurations. Intramolecular chargetransfer bands were observed for the molecules with strong substituents.The electron affinity of benzene was determined to be -1"1 +0"3 ev from the energy of the charge-transfer configuration estimated in such a way as to explain as well as possible the observed absorption spectra of the mono-substituted benzenes under consideration.

Measurements of mass-selected ion-current and threshold photoelectron spectra of jet-cooled aniline–Arn van der Waals complexes (n=1 and 2) have been carried out with a two-color resonantly enhanced multiphoton ionization (REMPI) technique using a high-resolution threshold photoelectron analyzer developed in this laboratory. From our (1+1′) REMPI experiments via the respective excited S1 states, we have obtained photoelectron spectra with well-resolved vibrational progressions due to ‘‘low-frequency van der Waals modes’’ of the cations; νvdW=16 cm−1 (n=1) and νvdW=11 cm−1 (n=2). From Franck–Condon calculations, we have assigned these low-frequency vibrations to the ‘‘van der Waals bending’’ of the cations. We have also found that the angles of the van der Waals bonds in the cations are changed by 8.2 (n=1) and 8.8 (n=2) degrees with respect to the S1 states. The adiabatic ionization potentials (Ia) of aniline and the aniline–Arn complexes (n=1 and 2) have been determined as 62 268±4 cm−1 (aniline), 62 157±4 cm−1 (n=1), and 62 049±4 cm−1 (n=2). Their shifts ΔIa are 111 cm−1 (n=1) and 219 cm−1 (n=2) with respect to aniline. Spectral shifts due to complex formation have been observed for a total of 13 ring modes of the cations.