Effect of external electric field on the tautomeric equilibrium and structure of 2‐carbamido‐1,3‐indandione

2‐Carbamido‐1,3‐indandione (CAID) is a new reliable fluorescent biomarker and it exists in two tautomeric forms: 2‐(hydroxyl‐aminomethylidene)‐indan‐1,3‐dione (A) and 2‐carboamide‐1‐hydroxy‐3‐oxo‐indan (B). The structures of the tautomers and the transition state for intramolecular proton transfer are located at MP2/6‐31+G(d) level for each magnitude and for opposite directions of the applied electric field. According to our SCS‐MP2/6‐31+G(d)...