Thiophenol stacking motions

An investigation on the thiophenol dimer and trimer was published in the Journal of Physical Chemistry Letters. The weakly-bound dimer adopts a stacked structure, while simultaneously maintaining a weak S-H路路路S hydrogen bond. Two isomers were detected for the dimer in the gas-phase. Notoriously, a large-amplitude motion was observed in one of the dimers, exchanging the proton donor and aceptor thiol groups.

 


Cracking DNA for students

Alberto Lesarri gave a talk at the “Diego de Praves” Secondary School in Valladolid last February 2, replicating the 1950’s DNA X-ray diffraction experiment with a laser pointer and a light bulb. This demonstration experiment basically shows the diffraction of an helix, giving opportunity to talk of the experimental work of Rosalind Franklin, as explained in 2018 in the American Journal of Physics.

You can compare the pointer diffraction, with the real pattern below:


Matrine isomerism

An investigation on matrine , a tetracyclic bis-quinolizidine alkaloid from the Sephora plants, was published in January 2021 in Journal 聽of Organic Chemistry. The molecule showed two (trans and cis) isomers in the gas-phase, confirming聽conformational rearrangements in matrine alkaloids. Matrine alkaloids have four stereogenic carbon centers, producing a large family of 16 stereoisomers in 8 enantiomeric pairs.


Serendipitous experiment

Chemistry World has informed that the group of Prof. Jens-Uwe Grabow in Hannover (Germany) recently reported a serendipitous experiment in which they observed a rare non-covalent interaction between a molecule of OCS and a Xe atom. The group was checking a microwave spectrometer when they noticed the rotational transitions from the OCS路路路Xe heterodimer. The original work is published in PCCP.

The PCCP TOC graphic (PCCP, 2020, 22, 5615)

COVID-19 exponentials

Category : General News

The COVID-19 pandemic has caused a planetary havoc. Vinod Bhardwaj reflects in his blog in centerforinquiry.org about the consequences of not understanding exponentials or math. Time to rely on science (and the WHO).

See the wonderful graphics of Our Word in Data for the COVID-19 evolution.

Total COVID-19 confirmed cases by beginning of April, from Our World in Data.

SDMC-2020

Alberto Lesarri gave a plenary talk at the Spectroscopy and Dynamics of Molecules and Clusters (SDMC-2020) Conference, which took place the last February 20-23 in Kumbhalgarh (Rajasthan, India). The Conference was jointly organized by聽Indian Institute of Technology (IIT, Jodhpur),聽Birla Institute of Technology and Science (BITS, Pilani),聽Malaviya National Institute of Technology (Jaipur),聽Indian Institute of Science Education and Research (Pune), and聽National Chemical Laboratory (Pune). The Conference was very dynamical, providing a great opportunity for scientific exchange. This was the first and probably the last Conference this year following the COVID-19 outbreak.


Mario Bunge

Prof. Mario Bunge, a well-known philosopher of Science died last February 25, 2020. Bunge was professor of Logic and Methaphysics at the McGill University and author of many books, including Philosophy of Science, but also a longtime fellow of the Committee for Skeptical Inquiry and has written several key articles on science and pseudoscience for Skeptical Inquirer.

The Bunge’s centenary Festchrift book and the cover of Phylosophy of Science.

IYPT Exhibition

Prof. Javier Garc铆a Martinez, Vicepresident of IUPAC 2020-22 gave a talk at the Faculty of Sciences last October 15, 2019, with the title “What is the IUPAC doing for you?“. The visit celebrated the new Exhibition on the Periodic Table organized in collaboration between the Spanish Society of Chemistry and the Faculty of Sciences. The exhibition includes all kind of periodic tables in different sizes and formats, together with an exhibition of books and bibliographic material at the Campus Library.

Prof. Javier Garc铆a Mart铆nez talks to the Faculty of Sciences.

One of the Periodic Tables in exhibition at the Faculty of Sciences.

Non-covalent interactions

We published in Chemistry: A European Journal a Minireview on rotational studies of non-covalent interactions, which appeared in the Reviews Showcase section of the Journal. In the article, entitled “The Hydrogen Bond and Beyond: Perspectives for Rotational Investigations of Non鈥怌ovalent Interactions“, we emphasize how the new broadband microwave techniques have boosted the possibilities for analyzing larger clusters and weaker interactions with rotational resolution.

The forest of non-covalent interactions has more trees than expected. Read the minireview to check out why.

Coherent rotational dynamics

Category : General News

The group of Prof. Jochen K眉pper at DESY & Uni. Hamburg have reported in Nature Communications the observation of the laser-induced rotational dynamics of OCS, or, in simple words, a “movie” of OCS rotating in the ps-scale time. In this experiment a rotational wavepacket is created on a molecular beam of OCS using two laser pulses. The beam is later probed with a third laser.

A cut of 18 picoseconds of the molecular movie of the OCS rotation (Credit: Nat. Comm. 10, 3364 (1019), Open Access under a CCA license)

A word of caution: Remember that molecular rotation is different to the rotation of a macroscopic stick, as microscopic objects are described by quantum mechanics.