GeneralInteresting ChemistryIonic SystemsChemical Sciences

How many water molecules does it take to ionise HCN/HNC? An NCI exploration.

https://doi.org/10.59350/x7f3m-9jb05
Published in Henry Rzepa's Blog

HCN is a weak acid (pKa +9.2, weaker than e.g. HF), although it does have an isomer, isocyanic acid or HNC (pka < +9.2 ?) which is simultaneously stronger and less stable. I conclude my halide acid series by investigating how many water molecules (in gas phase clusters) are required for ionisation of this “ pseudo-halogen ” acid.

References

The Houk–List transition states for organocatalytic mechanisms revisited

https://doi.org/10.1039/c3sc53416b
Published in Chem. Sci.
Authors Alan Armstrong, Roberto A. Boto, Paul Dingwall, Julia Contreras-García, Matt J. Harvey, Nicholas J. Mason, Henry S. Rzepa

The ten year old Houk–List model for rationalising the origin of stereoselectivity in the organocatalysed intermolecular aldol addition is revisited, using a variety of computational techniques that have been introduced or improved since the original study.

InChI=1S/CHN.H2O/c1-2;/h2H;1H2YBEMBCNSERFNHY-UHFFFAOYSA-N

C 1 H 3 N 1 O 1

https://doi.org/10.14469/ch/190935
Published
Authors Henry S Rzepa, Imperial College London, Imperial College London, Henry S Rzepa

# opt(calcfc,cartesian,maxcycles=500) wb97xd/6-311++g(2d,2p) integral=

InChI=1S/CHN.2H2O/c1-2;;/h2H;2*1H2BITDWVSGTSPFGI-UHFFFAOYSA-N

C 1 H 5 N 1 O 2

https://doi.org/10.14469/ch/190937
Published
Authors Henry S Rzepa, Imperial College London, Imperial College London, Henry S Rzepa

# opt(calcfc,cartesian,maxcycles=500) wb97xd/6-311++g(2d,2p) integral=

InChI=1S/CHN.3H2O/c1-2;;;/h1H;3*1H2YOKYLBBFQQSNCF-UHFFFAOYSA-N

C 1 H 7 N 1 O 3

https://doi.org/10.14469/ch/190938
Published
Authors Henry S Rzepa, Imperial College London, Imperial College London, Henry S Rzepa

# opt(calcfc,cartesian,maxcycles=500) wb97xd/6-311++g(2d,2p) integral=

InChI=1S/CHN.2H2O/c1-2;;/h1H;2*1H2HGVCDLHFLQXINL-UHFFFAOYSA-N

C 1 H 5 N 1 O 2

https://doi.org/10.14469/ch/190940
Published
Authors Henry S Rzepa, Imperial College London, Imperial College London, Henry S Rzepa

# opt(calcfc,cartesian,maxcycles=500) wb97xd/6-311++g(2d,2p) integral=

InChI=1S/CHN.4H2O/c1-2;;;;/h1H;4*1H2JHAHIMLETZTWSE-UHFFFAOYSA-N

C 1 H 9 N 1 O 4

https://doi.org/10.14469/ch/190951
Published
Authors Henry S Rzepa, Imperial College London, Imperial College London, Henry S Rzepa

# opt=(calcfc,cartesian,maxcycles=500) freq wb97xd/6-311++g(2d,2p) geo

InChI=1S/CHN.5H2O/c1-2;;;;;/h1H;5*1H2GPYAUIGGSKEHPM-UHFFFAOYSA-N

C 1 H 11 N 1 O 5

https://doi.org/10.14469/ch/190964
Published
Authors Henry S Rzepa, Imperial College London, Imperial College London, Henry S Rzepa

# opt=(calcall,cartesian,maxcycles=500) wb97xd/6-311++g(2d,2p) geom=co