Chemical SciencesWordPress

Henry Rzepa's Blog

Henry Rzepa's Blog
Chemistry with a twist
Home PageAtom Feed
language
Chemical ITAstronomyBinary StarsBlack HolesFamous Chemical ControversyChemical Sciences
Published

In 2016, the world heard that gravitational waves had been detected and now a third instance is reported. Given that the data associated with these detections are perhaps amongst the most important instances in recent times, I thought I might take a peek at how it was managed. The original report in 2016[cite]10.1103/PhysRevLett.116.061102[/cite] cited (Ref 116) data as DOI: 10.7935/K5MW2F23.

Chemical ITCrystal_structure_miningChemistryChloroform SolutionsConformational IsomerismChemical Sciences
Published

Conformational polymorphism occurs when a compound crystallises in two polymorphs differing only in the relative orientations of flexible groups ( e.g. Ritonavir).[cite]10.1039/D1SC06074K[/cite] At the Beilstein conference, Ian Bruno mentioned another type; ** tautomeric polymorphism**, where a compound can crystallise in two forms differing in the position of acidic protons. Here I explore three such examples.

Crystal_structure_miningCompany: CL ENGENHARIADerekDerek LoweLoweChemical Sciences
Published

Derek Lowe highlights a recent article[cite]10.1002/anie.201702626[/cite] postulating CH⋅⋅⋅π interactions in proteins. Here I report a quick check using the small molecule crystal structure database (CSD). The search query (DOI: 10.14469/hpc/2594) is shown below.

Chemical ITAppletCompression AlgorithmComputingCross-platform SoftwareChemical Sciences
Published

As the Internet and its Web-components age, so early pages start to decay as technology moves on. A few posts ago, I talked about the maintenance of a relatively simple page first hosted some 21 years ago. In my notes on the curation, I wrote the phrase “ Less successful was the attempt to include buttons which could be used to annotate the structures with highlights.

Crystal_structure_miningAlkeneAlkyneFunctional GroupsIntra-molecular SearchChemical Sciences
Published

Following on from my re-investigation of close hydrogen bonding contacts to the π-face of alkenes, here now is an updated scan for H-bonds to alkynes. The search query (dataDOI: 10.14469/hpc/2478) is similar to the previous one: QA is any of N,O,F,Cl. X is any atom, including metals and non-metals.

Crystal_structure_miningCalculated EnergyChemical BondingChemistryCrystalChemical Sciences
Published

Back in the early 1990s, we first discovered the delights of searching crystal structures for unusual bonding features.[cite]10.1039/P29940000703[/cite] One of the first cases was a search for hydrogen bonds formed to the π-faces of alkenes and alkynes. In those days the CSD database of crystal structures was a lot smaller (<80,000 structures; it’s now ten times larger) and the search software less powerful.