NLO and NBO Analysis of Sarcosine-Maleic Acid by Using HF and B3LYP Calculations

Table 1

Selected experimental and theoretical bond lengths and angles for sarcosine-maleic acid.

Parameters	Exp. [43]	Exp.	Exp.	Theoretical (6–31G++(d,p))
				HF	B3LYP
Bond lengths (Å)
Sarcosine
N1–C2	1.4818 (19)	1.481 (2) [9]	1.485 (3) [44]	1.474	1.469
N1–C3	1.4973 (19)	1.484 (2) [9]	1.485 (3) [44]	1.477	1.475
C1–C2	1.512 (2)	1.525 (2) [9]	1.497 (3) [44]	1.510	1.514
C1–O1	1.3099 (19)	1.271 (2) [9]	1.297 (3) [44]	1.310	1.346
C1–O2	1.2178 (18)	1.239 (2) [9]	1.297 (3) [44]	1.189	1.213
Maleic acid
C4–C5	1.500 (2)	1.473 (5) [45]	1.470 (5) [46]	1.507	1.507
C4–O3	1.2607 (19)	1.208 (6) [45]	1.217 (4) [46]	1.192	1.217
C4–O4	1.2640 (19)	1.303 (5) [45]	1.321 (5) [46]	1.309	1.335
O4–O5	—	2.427 (4) [45]	2.475 (4) [46]	2.583	2.625
O4–H11	—	1.030 [45]	0.940 (5) [46]	0.966	0.986
O5–H11	0.840	1.400 [45]	1.530 (5) [46]	1.627	1.652
C5–C6	1.338 (2)	1.318 (5) [45]	1.340 (5) [46]	1.329	1.348
C6–C7	1.497 (2)	1.480 (5) [45]	1.487 (5) [46]	1.505	1.489
C7–O5	1.2913 (19)	1.258 (4) [45]	1.286 (4) [46]	1.271	1.336
C7–O6	1.2317 (18)	1.250 (4) [45]	1.220 (4) [46]	1.219	1.225
Bond Angles (^o)
Sarcosine
N1–C2–C1	110.66 (11)	111.40 (2) [9]	111.55 (18) [44]	108.71	110.01
C2–C1–O1	112.39 (12)	115.20 (2) [9]	111.4 (2) [44]	112.07	111.78
C2–C1–O2	121.80 (13)	118.70 (2) [9]	122.8 (2) [44]	122.65	124.45
O1–C1–O2	125.80 (14)	126.10 (2) [9]	125.7 (2) [44]	125.12	123.74
C3–N1–C2	111.86 (11)	112.90 (2) [9]	114.31 (18) [44]	114.74	113.10
Maleic acid
C4–C5–C6	129.39 (14)	131.5 (3) [45]	131.7 (4) [46]	133.53	134.81
C4–O4–H11	—	108.0 [45]	107.0 (3) [46]	112.35	111.47
C5–C4–O3	116.99 (13)	120.0 (4) [45]	119.3 (3) [46]	118.01	118.05
C5–C4–O4	121.13 (14)	119.2 (4) [45]	120.4 (3) [46]	120.15	120.71
C5–C6–C7	130.71 (14)	130.6 (3) [45]	131.7 (4) [46]	131.61	132.68
C6–C7–O5	120.33 (13)	120.9 (3) [45]	118.8 (3) [46]	119.24	116.98
C6–C7–O6	118.94 (13)	117.0 (3) [45]	118.4 (3) [46]	117.13	120.46
O3–C4–O4	121.87 (14)	120.8 (4) [45]	120.3 (3) [46]	121.84	121.24
O5–C7–O6	120.72 (14)	122.1 (3) [45]	122.8 (3) [46]	123.64	122.57
C7–O5–H11	109.5	—	—	113.49	114.97