Symbiosis between computation and experiment is increasingly evident in pedagogic journals such as J. Chemical Education. Thus an example of original laboratory experiments[cite]10.1021/ed077p271[/cite],[cite]10.1021/ed078p1266[/cite] that later became twinned with a computational counterpart.[cite]10.1021/ed500398e[/cite] So when I spotted this recent lab experiment[cite]10.1021/acs.jchemed.7b00566[/cite] I felt another twinning approaching.
Posts Tagged ‘Ammonium’
Organocatalytic cyclopropanation of an enal: (computational) mechanistic understanding.
Saturday, August 25th, 2018Ammonide: an alkalide formed from ammonia and resembling an electride.
Sunday, December 17th, 2017Alkalides are anionic alkali compounds containing e.g. sodide (Na–), kalide (K–), rubidide (Rb–) or caeside (Cs–). Around 90 examples can be found in the Cambridge structure database (see DOI: 10.14469/hpc/3453 for the search query and results). So what about the ammonium analogue, ammonide (NH4–)? A quick search of Scifinder drew a blank! So here I take a look at this intriguingly simple little molecule.‡
Ammonium tetraphenylborate and the mystery of its π-facial hydrogen bonding.
Friday, March 10th, 2017A few years back, I did a post about the Pirkle reagent[cite]10.1039/c39910000765[/cite] and the unusual π-facial hydrogen bonding structure[cite]10.1039/P29940000703[/cite] it exhibits. For the Pirkle reagent, this bonding manifests as a close contact between the acidic OH hydrogen and the edge of a phenyl ring; the hydrogen bond is off-centre from the middle of the aryl ring. Here I update the topic, with a new search of the CSD (Cambridge structure database), but this time looking at the positional preference of that bond and whether it is on or off-centre.
How many water molecules does it take to form ammonium hydroxide from ammonia and water?
Sunday, March 20th, 2016This is a corollary to the previous post‡ exploring how many molecules are needed to ionise HCl. Here I am asking how many water molecules are required to form the ionic ammonium hydroxide from ammonia and water.