TY - JOUR
T1 - More Electropositive is More Electronegative
T2 - Atom Size Determines C=X Group Electronegativity
AU - Nieuwland, Celine
AU - Verdijk, Ron
AU - Fonseca Guerra, Célia
AU - Bickelhaupt, F. Matthias
N1 - Publisher Copyright:
© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.
PY - 2024/3/12
Y1 - 2024/3/12
N2 - Opposite to what one might expect, we find that the C=X group can become effectively more, not less, electronegative when the Pauling electronegativity of atom X decreases down Groups 16, 15, and 14 of the Periodic Table. Our quantum-chemical analyses, show that, and why, this phenomenon is a direct consequence of the increasing size of atom X down a group. These findings can be applied to tuning and improving the hydrogen-bond donor strength of amides H2NC(=X)R by increasingly withdrawing density from the NH2 group. A striking example is that H2NC(=SiR2)R is a stronger hydrogen-bond donor than H2NC(=CR2)R.
AB - Opposite to what one might expect, we find that the C=X group can become effectively more, not less, electronegative when the Pauling electronegativity of atom X decreases down Groups 16, 15, and 14 of the Periodic Table. Our quantum-chemical analyses, show that, and why, this phenomenon is a direct consequence of the increasing size of atom X down a group. These findings can be applied to tuning and improving the hydrogen-bond donor strength of amides H2NC(=X)R by increasingly withdrawing density from the NH2 group. A striking example is that H2NC(=SiR2)R is a stronger hydrogen-bond donor than H2NC(=CR2)R.
KW - Amides
KW - Atomic size
KW - Chemical bonding
KW - Electronegativity
KW - Hydrogen bonding
KW - Supramolecular chemistry
UR - https://www.scopus.com/pages/publications/85182236121
U2 - 10.1002/chem.202304161
DO - 10.1002/chem.202304161
M3 - Article
C2 - 38117278
AN - SCOPUS:85182236121
SN - 0947-6539
VL - 30
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 15
M1 - e202304161
ER -