Structural, Electronic, and Vibrational Properties of Isoniazid and Its Derivative N-Cyclopentylidenepyridine-4-carbohydrazide: A Quantum Chemical Study

Table 5

Lowest energy, HOMO-LUMO gap (frontier orbital energy gap) and dipole moment of isoniazid and N-cyclopentylidenepyridine-4-carbohydrazide (CPPC) by (B3LYP)/6-311 G (d, p) and (B3LYP)/LANL2DZ methods.

Parameters	Isoniazid		N-Cyclopentylidenepyridine-4-carbohydrazide
	LANL2DZ	6-311 G (d, p)	LANL2DZ	6-311 G (d, p)
Energy (in au)	−472.2226	−472.4245	−666.3336	−666.6202
Dipole moment (in Debye)	5.49	4.94	6.25	5.37
HOMO	−6.8353	−6.8852	−6.7673	−6.7821
LUMO	−1.8800	−1.9129	−1.9815	−1.9875
Frontier orbital energy gap (eV)	4.9552	4.9723	4.7857	4.7946