Compd.	υ(OH)	υ(NH₂)	υ(C≡N)	υ(C=O); Amide I band	υ(NH₂)	Amide II band	υ(N-N)	υ(M-O)	υ(M-N)	λ(nm) in υ (cm⁻¹), Nujol	U_eff (BM)
L¹	____	3280, 3199	2263	1710, 1680	1619	1530, 1492	998	........	.......	257.3, 38,865	−1.95
1	3440	3182, 2997	2264	1660, 1634	1586	1519, 1435	975	440	350	800, 12,500	1.95
2	3400	3320, 3185	2260	1720, 1670	1589	1401	940	400	335	740, 13,514	0.91
3	____	3445, 2993	2264	1760, 1640	1585	1440, 1360	980	440	388	800, 12,500	1.24
4	3400	3180, 3100	2264	1710, 1640	1582	1440, 1400	975	439	385	780, 12,821	1.02
5	____	3180, 3210	____	1700, 1650	1585	1445, 1395	976	425	390	780, 12,821	1.14
6	____	3415, 3346	2270	1740, 1600	1540	1406, 1300	940	400	360	830, 12,408	0.78
7	3480	3220, 3170, 2980	____	1636	1618	1575, 1540	955	400	345	760, 13,158	0.75
8	3350	2968, 2930, 2800	2260	1720	1590	1529, 1402	940	440	399	750, 13,333	0.85
9	3440	3280, 3231, 3180	____	1638	1620	1572, 1440	940	433	400	760, 13,158	0.86, 0.89
10	3426	3200, 2987	2263	1700, 1660	1590	1531, 1430	980	440	400	780, 12,821	0.78
11	3420	3260, 3200	2260	1700	1621	1540, 1416	953	450	389	740, 13,514	0.84
12	3426	3200	2263, 2170	1700, 1660	1590	1537, 1430	940	440	400	730, 13,699	0.88