Synthesis, Spectroscopic, Molecular Structure, and Antibacterial Studies of Dibutyltin(IV) Schiff Base Complexes Derived from Phenylalanine, Isoleucine, and Glycine

Table 4

¹³C NMR spectral data of the ligands and their corresponding organotin(IV) complexes.

Compounds	Chemical shift in ( ppm)
	COOH	CH	C=N	CH2/CH3	Aromatic carbons	Sn–^αCH2^βCH2^γCH2^δCH3
L^1H	176.8	67.8	163.4	38.2	149.2, 135.8, 133.0, 128.6, 127.5, 126.3, 124.6, 122.9, 120.1	—
Bu2Sn(L^1)2	185.4	65.7	155.2	39.4	150.0, 136.1, 132.6, 128.2, 127.1, 126.5, 124.4, 123.3, 120.2	C-α, 22.2; C-β, 25.6; C-γ, 22.4; C-δ, 13.4
L^2H	178.5	65.7	162.4	16.3, 21.3	145.8, 133.2, 130.5, 126.2, 124.0, 119.3	—
Bu2Sn(L^2)2	184.9	66.2	154.6	17.4, 22.1	146.2, 132.9, 130.8, 126.54, 124.3, 120.1	C-α, 21.4; C-β, 25.3; C-γ, 21.6; C-δ, 13.5
L^3H	176.1	—	163.6	52.4	148.5, 131.0, 129.8, 125.3, 122.9, 119.1	—
Bu2Sn(L^3)2	183.7	—	154.5	58.3	149.0, 132.5, 129.6, 125.7, 123.4, 119.6	C-α, 22.1; C-β, 25.2; C-γ, 22.3; C-δ, 14.1
L^4H	178.5	65.7	162.4	39.1	150.2, 136.1, 132.8, 129.5, 127.3, 126.4, 123.2, 122.4, 119.8	—
Bu2Sn(L^4)2	184.5	66.2	154.5	38.7	149.5, 135.7, 132.1, 130.4, 126.9, 126.2, 123.5, 122.1, 120.3	C-α, 22.4; C-β, 26.7; C-γ, 22.8; C-δ, 14.6
L^5H	177.5	66.2	163.1	17.3, 20.5	147.7, 132.8, 131.3, 126.6, 123.8, 120.3	—
Bu2Sn(L^5)2	184.1	67.4	153.8	18.0, 20.2	148.1, 132.4, 129.7, 126.5, 124.0, 120.2	C-, 22.0; C-, 26.1; C-, 22.5; C-, 13.4
L^6H	176.9	—	162.9	55.4	149.5, 132.8, 128.9, 125.7, 123.0, 120.3	—
Bu2Sn(L^6)2	182.8	—	155.4	56.1	148.2, 133.1, 128.5, 125.8, 122.7, 120.5	C-α, 21.2; C-β, 25.3; C-γ, 22.24; C-δ, 13.7