Frédéric A. Perras

Counterintuitively, here your peak shifts upfield as the magnetic field decreases. We should really avoid using these terms as they are evidently confusing and obviously antiquated.

I sent you an email.

In undergrad the University of Ottawa offered a scientific communication class for chemistry students. It covered how to read, organize, and write a scientific paper, what not to do, and how to communicate in general. It was fantastic. Dave had provided some NMR examples of particularly bad writing.

Biomolecular NMR Facility Manager Position Title: Biomolecular NMR Facility Manager Job Group: Professional & Scientific Required Minimum Qualifications: Bachelor’s degree and 5 years of related experience Preferred Qualifications...

Iowa State Dept of Molecular Biology is hiring for biomolecular solution NMR facility staff #NMRchat #Chemjobs #Chemsky

(I am NOT the hiring manager for this position, but I will refer any questions you have to the appropriate person.) isu.wd1.myworkdayjobs.com/IowaStateJob...

DFT calculations and theory do not support enantiospecificity in NMR J-coupling constants - Nature Communications Nature Communications - DFT calculations and theory do not support enantiospecificity in NMR J-coupling constants

Josef Zwanziger, @aaronrossini.bsky.social, and I published a rebuttal of a recent Nature Commun. paper claiming that enantiomers produce large differences in J coupling constants.

doi.org/10.1038/s414...

Falcon Space - Advanced Propulsion Research & Development Falcon Space is working to make the dream of advanced propulsion a reality through innovative experiments and UAP Reverse-Engineering.

Apparently, there is a company using DNP (yes, specifically DNP-NMR) for.... propulsion in warp drives?
www.falconspace.org

Those fits to the CP build-up curves are incredible. Very nice.

Lab director on building occupation: ‘Protesters are in mortal danger’ - Vox magazine The occupation of the Goudsmitpaviljoen could be life-threatening, warns lab director Arno Kentgens. He urges the campaigners to allow technicians access at all times. ‘The protesters could suffocate ...

Crazy event. Here is another article that is not pay-walled:
www.voxweb.nl/en/lab-direc...

We prepared a 17O-enriched boron monoxide material which allowed us to gain a greater clarity on the long-range structure of the material. Data seems to point at BO being a 1D polymer. Same structure as initially proposed in 1955.

doi.org/10.1039/D5CC...

Sorry to hear that. I hope you get better soon.

I will die on this hill; lacquer is the superior finish. Spray on, always perfect, ready to recoat basically after you are done spraying the last one.

DFT calculations with the ADF program can now 𝗽𝗿𝗲𝗱𝗶𝗰𝘁 𝘁𝗵𝗲 𝗢𝘃𝗲𝗿𝗵𝗮𝘂𝘀𝗲𝗿 𝗲𝗳𝗳𝗲𝗰𝘁 𝗶𝗻 𝗗𝗡𝗣 𝗿𝗮𝗱𝗶𝗰𝗮𝗹𝘀. Computed hyperfine couplings and rotation barriers match experiments, showing computational chemistry can guide radical design before synthesis. zurl.co/7iJHH #matsky #compchemsky

Determining the Conformation of Supported Complexes Using an 17O TEDOR-like NMR Experiment Dynamic nuclear polarization surface-enhanced nuclear magnetic resonance (NMR) spectroscopy has enabled the determination of the three-dimensional configuration of surface sites, in particular supported metal complexes of relevance to single-site heterogeneous catalysis. These approaches have chiefly leveraged the application of NMR double-resonance experiments that either reveal the complex conformation via point-to-point intramolecular distances between spin-labeled atoms or the complex-surface orientation via distances between the spins and the surface plane. Either method typically requires expensive isotope labeling and each reports on different structural features. The application of an experiment that simultaneously reveals both types of distances with chemical resolution would be ideal. In this article, we describe an 17O{1H} pseudo-3D correlation experiment that achieves this goal. Specifically, Si–O–Si and Si–O–M oxygens are well-resolved by 17O NMR; therefore, distances can be simultaneously measured radially, between Si–17O–M and the 1H’s of the ligands, and vertically to the Si–17O–Si linkages of the silica support. We demonstrate the experiment using supported yttrium and zirconium complexes. Good agreement is obtained when comparing the experimental results to theoretical predictions from density functional theory calculations, highlighting the reliability of this relatively simple experiment.

Can you use DNP-enhanced 1H-17O D-RINEPT build-up curves to measure more or less "free" geometrical information in grafted metal complexes?

doi.org/10.1021/acs....

(Yes!)

For the second point, Ln(III) cations are largely chemically identical. Their f orbitals behave as core orbitals and do not participate in bonding. So while the total spin and orbital angular momentum will change, the bonding and spin density functions should be close to the same.

I am about as far from being an expert as there is, but regarding point 1, the Fermi contact interaction required spin density exactly on the nucleus. So it basically measures the amount of of the spin density function that is made up of that atom's s orbitals.

When performing spin dynamics simulations under MAS, it is necessary to do 3-angle averaging. Conventionally this is done with 2-angle averaging and a gamma-carousel average. We show that this convention should be avoided in favor of proper integrated 3-angle averaging.
doi.org/10.1016/j.jm...

Love it!

I am saddened and shocked to hear of the passing of Jean-Nicholas Dumez. I admired his work, and used it as inspiration for much of the work I am most proud of. The NMR community has lost one of its best young scientists.

Twitter used to be nice, and then most of the posts I was seeing were promoted posts and ads. When I quit "X" and created a bluesky account it was such a breath of fresh air and quite reminiscent of what Twitter was like when I decided to join to find and promote papers.

I have not tried it but these stores I read make me wonder why Bruker goes out of their way to avoid using Redhat. Redhat costs about the same as windows. On an instrument that typically costs over $1M... Agilent would just give you a Redhat workstation.

New nuclear quadrupole moments just dropped for 7Li and 27Al. The 7Li one is actually significantly different from the previous estimation. The 27Al one seems to instead simply include more significant figures.

doi.org/10.1021/acs....

Synthesis and Properties of Poly(vinyl chloride)-b-polyethylene Multiblock Copolymers through the Hydrodechlorination of PVC with Silylium Ions Block copolymers of polyethylene (PE) and polyvinyl chloride (PVC) have remained elusive materials despite PE and PVC being the first and third most produced polymers globally, respectfully. The closest material is chlorinated polyethylene (CPE), which is commonly used as a compatibilizer and is synthesized by functionalizing PE. However, there does not exist a synthetic pathway either from monomers or via the functionalization of PE to yield a polymer that has a controlled chlorine amount and primary structure along the polymer chain. Herein, we report a series of novel block copolymers of PVC and PE, synthesized through selective hydrodechlorination of PVC. Contrary to CPE, the full range of chlorination can be obtained, and the block number can be altered. Interfacial adhesion studies reveal samples with competitive compatibilization of PVC/polyolefin elastomer (POE) blends. This method shows that postpolymerization modification can be a strategic top-down synthesis to achieve high-performance polymers that cannot be synthesized via conventional polymerization pathways.

Work led by Megan Fieser led to the first synthesis of PE-PVC block copolymers.

Crazy that it took so long to make block copolymers of two of the top 3 plastics. It is an interesting read if you simply want to find out why it was such a challenge (and how it was done).

doi.org/10.1021/jacs...

Surface Protected Organozirconium Catalyzes C–H Alumination of Saturated Hydrocarbons Surface grafted organozirconium-catalyzes C–H/Et–Al exchange reactions, involving saturated hydrocarbons and AlEt3, to afford organoaluminum compounds and ethane. The Zr(OtBu)3@SiO2-Al2O3-700 (1) cat....

Work led by the Sadow lab. Post-grafting capping of surface hydroxyls improves the longevity of supported organometallic catalysts that would otherwise degrade when exposed to alkylaluminum reagents.

doi.org/10.1002/anie...

My colleague Takeshi Kobayashi came up with this ingenious way of protecting sensitive samples from the atmosphere for MAS investigation by grinding the particles into a perdeuterated wax matrix.

We are already routinely using this method for studies of SOMC catalysts.

doi.org/10.1016/j.jm...

Ultra-Confined Environments May Restrict the Possible Configurations of Supported Metal Complexes The rotation frequencies of amido ligands are highly sensitive to the electronic structure of d0 transition metal complexes and have been used to study ligand donor properties. While attempting to study the donor properties of silanolate ligands in a silica-supported Cr complex, we observed highly restricted motions due to the added steric hindrance from the support, with only approximately half of the amides rotating on a 50 ms time scale. Surprisingly, when the same species is grafted into narrow 2.2 nm pores, all amido ligands are able to rotate. Density functional theory calculations suggest that confinement may limit the possible coordination sites and the configuration of the formed surface species, potentially enabling the formation of conformationally homogeneous surface site populations.

We found that supported complexes behave counterintuitively in highly-confined environment where sterics lead to selective site population of highly-dynamic species.

doi.org/10.1021/acs....

Iterative baseline correction algorithm for dead time truncated one-dimensional solid-state MAS NMR spectra We present an algorithm suitable for automatically correcting rolling baseline coming from time-domain truncation induced by the dead time in pulse-ac…

This is the feature I wish topspin added:
www.sciencedirect.com/science/arti...

On the downside, now, syncing with the file system used to be instantaneous and now it takes a very measurable amount of time. Quite a strange choice.

Really? I am pretty sure I did do this, but maybe I am misremembering.

Topspin has a search now? What is the use case?

I still think that topspin 1.3 was peak Topspin.

I am sorry for your loss. Words cannot express.