Archive for August, 2017
Thursday, August 31st, 2017
Conferences can be intense, and this one is no exception. After five days, saturation is in danger of setting in. But before it does, I include two more (very) brief things I have learnt.
(more…)
Tags:gas phase, Interesting chemistry, journalist, Magnetism, Pavel Hobza, Saturation, Semiconductors - NEC, synthetic chemist, ultrasound
Posted in WATOC reports | 4 Comments »
Tuesday, August 29th, 2017
Another selection (based on my interests, I have to repeat) from WATOC 2017 in Munich.
- Odile Eisenstein gave a talk about predicted 13C chemical shifts in transition metal (and often transient) complexes, with the focus on metallacyclobutanes. These calculations include full spin-orbit/relativistic corrections, essential when the carbon is attached to an even slightly relativistic element. She noted that the 13C shifts of the carbons attached to the metal fall into two camps, those with δ ~+80 ppm and those with values around -8 ppm. These clusters are associated with quite different reactivities, and also seem to cluster according to the planarity or non-planarity of the 4-membered ring. There followed some very nice orbital explanations which I cannot reproduce here because my note taking was incomplete, including discussion of the anisotropy of the solid state spectra. A fascinating story, which I add to here in a minor aspect. Here is a plot of the geometries of the 52 metallacyclobutanes found in the Cambridge structure database. The 4-ring can be twisted by up to 60° around either of the C-C bonds in the ring, and rather less about the M-C bonds. There is a clear cluster (red spot) for entirely flat rings, and perhaps another at around 20° for bent ones, but of interest is that it does form something of a continuum. What is needed is to correlate these geometries with the observed 13C chemical shifts to see if the two sets of clusters match. I include this here because in part such a search can be done in “real-time” whilst the speaker is presenting, and can then be offered as part of the discussion afterwards. It did not happen here because I was chairing the meeting, and hence concentrating entirely on proceedings!
(more…)
Tags:chemical shifts, Chemistry, City: Munich, Interesting chemistry, Jan Jenson, metal fall, Munich, Odile Eisenstein, Quotation, speaker, Stefan Grimme, Transition metal, Walter Thiel, World Association of Theoretical and cOmputational Chemists
Posted in WATOC reports | 6 Comments »
Tuesday, August 29th, 2017
The triennial conference is this year located in Munich. With 1500 participants and six parallel sessions, this report can give only a flavour of proceedings.
(more…)
Tags:bond dissociation energy, City: Aachen, City: Munich, Dieter Cremer, Edward Valeev, energy, Flavour, Interesting chemistry, Jeremy Harvey, Ken Houk, Leo Radom, Peter Scheiner, Physics, Proceedings, Quark matter, Standard Model, Yitzhak Apeloig
Posted in WATOC reports | No Comments »
Saturday, August 12th, 2017
At the moment, the bond slam is something of a home from home for this blog and since much of my activity is happening there rather than here, I thought I might give you pointers to some of the topics, which are evolving, so to speak, before our very eyes.
(more…)
Tags:Interesting chemistry
Posted in Uncategorised | No Comments »
Wednesday, August 2nd, 2017
It is always interesting to observe conference experiments taking place. The traditional model involves travelling to a remote venue, staying in a hotel, selecting sessions to attend from a palette of parallel streams and then interweaving chatting to colleagues both old and new over coffee, lunch, dinner or excursions. Sometimes conferences occur in clusters, with satellite meetings breaking out in the vicinity, after a main conference has done the job of attracting delegates to the region. Here I bring to your attention one such experiment, the Bond Slam which is part of a satellite meeting in Aachen to be held September 2-4 2017 on the topic of Chemical Bonds at the 21st Century, following on from the WATOC 2017 congress in Munich Germany a few days earlier.
(more…)
Tags:Interesting chemistry
Posted in Bond slam | 3 Comments »