Making accurate, quantitative predictions of chemical reactivity based on molecular structure is an unsolved problem in chemical synthesis, particularly for complex molecules. We report an approach to reactivity prediction for...

Pressurized sample infusion (PSI) is a simple and effective means of continuously introducing a solution to an electrospray ionization mass spectrometry (ESI‐MS) source. It allows for acquisition of real‐time data in an air‐ and moisture‐free environment and requires minimal additional infrastructure. It is applicable for use for any reaction in which one or more components are detectable by ESI‐MS and for which time‐course information is desired over a time scale of seconds to minutes. The strengths and weaknesses of the method are critically examined, and technique tips and tricks are provided to enable maximal effectiveness when employing this approach to continuous monitoring of complex reaction mixtures.

Mass spectrometric data are copious and generate a processing burden that is best dealt with programmatically. PythoMS is a collection of tools based on the Python programming language that assist researchers in creating figures and video output that is informative, clear, and visually compelling. The PythoMS framework introduces a library of classes and a variety of scripts that quickly perform time-consuming tasks: making proprietary output readable; binning intensity vs time data to simulate longer scan times (and hence reduce noise); calculating theoretical isotope patterns and overlaying them in histogram form on experimental data (an approach that works even for overlapping signals); rendering videos that enable zooming into the baseline of intensity vs time plots (useful to make sense of data collected over a large dynamic range) or that depict the evolution of different species in a time-lapse format; calculating aggregates; and providing a quick first-pass at identifying fragments in MS/MS spectra. PythoMS is a living project that will continue to evolve as additional scripts are developed and deployed.

Gas-phase oxidation of air-sensitive organometallic compounds does not proceed to a significant extent in mass spectrometric analysis unless a vacant coordination site is generated, making nitrogen generators a suitable source of desolvation gas.

The cover art blends together some experimental details -the pressurized, modified Schlenk flask used in the PSI experiments, and the tubing that leads out into the mass spectrometer -with the reaction traces generated while performing the experiment. The design was constructed using 3D modelling software and superimposed on a background of a lake bed for some added visual interest before rendering. What time-consuming dead-ends delayed the results before this breakthrough?Clogging of the PEEK tubing when working with heterogeneous solutions would often result in flow restrictions, causing delays in getting timely reaction monitoring results. Luckily our work with simple filter attachments has helped to streamline the data acquisition process. What do you consider the exciting developments in the field?The ability to acquire data online and in real time. This provides a unique perspective of reactions as information can be inferred Invited for this month's cover is the group of Scott McIndoe at the University of Victoria (Canada). The cover picture shows a pressurized reaction vessel with tubing leading out of the flask. That tubing normally leads directly into an electrospray ionization mass spectrometer, where the mass-to-charge ratio and relative abundance of the solution phase ions are measured. These data can be used to generate chronograms for each solution species, shown here in the form of a reactant diminishing with first order kinetics, accompanied by the formation of a product ion. Read the full text of their Review at 10.1002/ cmtd.202100068. Chemistry-Methods www.chemistrymethods.org

Catalytic reactions are limited in their turnover by certain steps in the cycle. We present a free, web-based interface where the rate constants of various steps in a cycle can be visualized. Population of a web form using known data will generate a highly customizable graphic for annotation by the user to represent their chemistry.

Zeise's salt, [PtCl 3 (H 2 C=CH 2)] À , is the oldest known organometallic complex, featuringe thylene strongly boundt oap latinum salt. Many derivatives are known,b ut none involving dinitrogen,a nd indeed dinitrogen complexesa re unknown forb oth platinum and palladium. Electrospray ionizationm ass spectrometry of K 2 [PtCl 4 ]s olutions generate strong ions corresponding to [PtCl 3 (N 2)] À ,t he identity of which wasc onfirmed through ion-mobility spectrometry and MS/MSe xperiments that proved it to be distinct from its isobaric counterparts [PtCl 3 (C 2 H 4)] À and [PtCl 3 (CO)] À .C omputationala nalysise stablished ag as-phase platinum-dinitrogen bond strength of 116kJmol À1 ,s ubstantially weaker than the ethylene and carbonm onoxidea nalogues but stronger than for polar solvents such as water,m ethanol and dimethylformamide, and strong enough that the calculated NÀN bond length of 1.119 represents weakening to ad egree typical of isolated dinitrogen complexes.

<p>Catalytic reactions are limited in their turnover by certain steps in the cycle. We present a free, open-source, web-based interface to generate visualizations of the rate constants of various steps in the cycle. Population of a web form using known data will generate a highly customizable graphic for annotation by the user to represent their chemistry.</p>