Monthly Archives: January 2019

Jon T. Hougen

Category : Sin categoría

Jon T. Hougen passed away last January 28, 2018. A former senior researcher at NIST and Editor of Journal of Molecular Spectroscopy, he was one of the best known international figures in the field of high-resolution spectroscopy and a permanent presence in international conferences worldwide. He will be remembered by his multiple contributions, including the treatment of large-amplitude motions and the development of permutation-inversion group theory. Two volumes of Journal of Molecular Spectroscopy were dedicated to him in 2017, on the ocassion of his 80th anniversary. Despite his official retirement in 2009 he never stopped contributing with new science.

Jon Hougen in a characteristic pose in one of his last Conferences last September 4, 2018 at the 25th HighResolution Molecular Spectroscopy meeting in Bilbao, Spain (Per Jensen appears at his right).

Ultima Thule

The end of 2018 and new year was full of space research news. In a very short time the Japanese Hayabusa2 touched an asteroid, the New Horizons spacecraft reached the Kuiper belt object Ultima Thule, and the Chinese probe Chang’e landed the Jade Rabbit 2 rover in the far side of the moon. The flyby of Ultima Thule is particularly interesting considering the distance of 6500 millions of km (equivalent to a radio attenuation of 303 dB at 7 GHz) and the fact that it was reached with about 35% of the remaining hydrazine fuel. New Horizons is expected to head towards another Kuiper object in the next years.

Two NASA images of Ultima-Thule taking in January 2019.
The Chinese lander on the far side of the moon.

Aniline trimer

A rotational investigation of the aniline trimer was published in Angewandte Chemie. The work, done in collaboration with Cristobal Pérez (Hamburg) and Brooks Pate (Virginia), found three isomers of the aniline trimer and two isomers of the monohydrated dimer. The trimer is more complex than the analogue phenol trimer, where the stronger O-H···O interaction produce a single (symmetric) isomer. In the aniline trimer, stabilized by N-H···N and N-H···Pi, interactions one of the observed species is also a symmetric rotor.

The figure shows the symmetric isomer of the aniline trimer, observed in a jet expansion.