Proton sponge → HCID 131718234, compound
Reaction equation
[OH2:1].[OH2:2].O.O.[C:5]([O-:8])(=[O:7])[CH3:6].[Gd+3].[C:10]([O-:13])(=[O:12])[CH3:11].[C:14]([O-])(=[O:16])C.CN(C1C2C(N(C)C)=CC=CC=2C=CC=1)C>C(Cl)(Cl)Cl.CO>[CH3:5][OH:7].[C:11]([OH:2])(=[O:1])[C:10]([OH:13])=[O:12].[OH:16][CH2:14][CH:6]([CH2:5][OH:8])[OH:12]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
The sp3 form of ligand 11 (42 mg, 0.08 mmol) was stirred with gadolinium acetate tetrahydrate (122 mg, 0.3 mmol) and proton sponge (54 mg, 0.25 mmol) in chloroform/methanol (150 ml, v/v 1/2) for one day. The dark green reaction mixture was concentrated under reduced pressure and chromatographed through silica gel (25 cm.×1.5 cm.) which was pretreated with chloroform/triethylamine (50 ml, v/v 25/1). Chloroform/triethylamine (25/1) and chloroform/methanol/triethylamine 25/2.5/1 v/v) was used as eluents. A dark red band was first collected followed by two green bands. The last green band, which showed a clear aromatic pattern by UV/VlS, was concentrated and recrystallized from chloroform/n-hexane to give 14 mg (22%) of the Gd complex 7BFor 7BFAB MS (methanol/oxalic acid/glycerol matrix): m/e (relative intensity) 671 (155G, 58), 672 (156Gd, 78), 673 (157Gd, 94), 674 (158Gd, 100), 676 (160Gd, 64); HRMS, M+ 674 2366 (calcd. for C34H38N5158Gd 674.2368): UV/VIS (CHCl3) λmax nm (ε) 339.5 (14,850), 450.5 (36,350), 694.5 (6,757), 758.0 (23,767); IR (KBr) ν2990, 2960, 2900, 2830, 2765, 2700, 2620, 2515, 1710, 1550, 1440, 1410, 1395, 1365, 1265, 1220, 1180, 1150, 1105, 1090, 1060, 1040, 1095, 1045, 1015, 680 cm-1 ; Anal. calc. for C34H38N5Gd.(OH)2.2H2O: C, 54.89; H, 5.96; N, 9.41. Found: C, 54.49; H, 5.95; N, 8.97.