The First Metal Complexes of 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione: Preparation, Physical and Spectroscopic Studies, and Preliminary Antimicrobial Properties

Table 2

Diagnostic ligand IR bands (cm⁻¹) for LH and complexes 1–10.

Compound	𝑣as(NH2)^a	𝑣s(NH2)	𝑣(N–H)	𝑣(C=N), 𝑣(C=C)	𝑣(C2-N1), 𝑣(C2-N3)	𝛿(NH)	𝑣(C=S)
LH	3390	3185	2970	1652	1652	1455	1177
1	3377, 3330	3180, 3156	3005	1631	1553	1460	1155
2	3388, 3356	3188, 3160	3000	1633	1556	1465	1170
3	3399, 3343	3180, 3079	3010	1632	1558	1464	1157
4	3400, 3320	3160, 3105	3005	1642	1560	1460	1170
5	3387, 3320	3166, 3110	3010	1635	1556	1455	1177
6	3380, 3357	3170, 3095	3015	1641	1552^b	1443^b	1176
7	3395, 3357	3164, 3098	3010	1646	1550	1446	1170
8	3397, 3360	3165, 3100	3015	1640	1553	1450	1176
9	3400, 3355	3155, 3105	3012	1639	1555^b	1460^b	1170
10	3405, 3324	3180, 3100	3010	1641	1558	1462	1164

^aOverlapping with the 𝑣(OH)_water band in the spectra of 1–8.
^bOverlapping with phenyl stretching vibrations of the coordinated PPh₃ ligands.