Synthesis and Characterization of [2-(carboxy methylene-amino)- phenyl imino] acetic acid (L) and its some metal complexes Dr. Jasim Shihab. Sultan*, prof. Dr.Falih Hussan. Mosa* Department of Chemistry, College of Education, Ibn-Haitham, University of Baghdad. * Address to *
N- substituted imines, also known as Schiff bases, have been used extensively as ligands in the field of coordination chemistry, furthermore the Schiff bases are very important tools for the inorganic chemists as these are widely used to design molecular ferromagnets, in catalysis, in biological modeling applications, as liquid crystals and as heterogeneous catalysts. Glyoxilic acid and its derivatives play important roles in natural processes, participating in glyoxylate cycle which functions in plants and in some microorganisms. Physical- chemical study of complexation of glyoxilic acid aroyl hydrazones with Cu(I) in solution and solid phase is reported. Introduction
Instrumentation 1. FTIR spectra were recorded in KBr on Shimadzu Spectrophotometer in the range of ( cm –1 ). 2. The electronic spectra in H 2 O were recorded using the UV-Visible spectrophotometer type (spectra nm) CECIL, England, with quartz cell of (1 cm) path length. 3. The melting point was recorded on "Gallen kamp Melting point Apparatus". 4. The Conductance Measurements were recorded on W. T. W. conductivity Meter. 5. Metal analysis. The metal contents of the complexes were determined by atomic absorption (A. A.) technique. Using a shimadzu PR-5. ORAPHIC PRINTER atomic obsorption spectrophotometer. 6. Balance Magnetic Susceptibility model MSB-MLI Al-Nahrain University 7. The characterize of new ligand (L) is achieved by: A: 1 H and 13 C-NMR spectra were recorded by using a bruker 300 MHZ (Switzerland). Chemical Shift of all 1 H and 13 C-NMR spectra were recorded in (ppm) unit downfield from internal reference tetramethylsilane (TMS), using D2O as a solvent. B: Elemental analysis for carbon, hydrogen for ligand and its complexes were using a Euro Vector EA 3000 A Elemental Analysis (Italy). C: These analysis (A and B) were done in at AL-al-Bayt University, Al- Mafrag, Jordan.
1. Ligand Synthesis Solubility Found (Calc.) % effect Colour M.P. C Yield % Empirical formula metalNHC Water, methanol, ethanol, ether, acetone, DMF, DMSO - (13.06) (3.64) 3.63 (54.60) Light brown 17086L=C 10 H 8 N 2 O 4 Synthesis Table (1): The physical properties for synthesized lignad (L)
Table (2a): 1 H-NMR Chemical Shifts for Ligand (L) (ppm in D 2 O) COOHHC=N Undeurated DMSO Water in DMSO WaterAromatic protons 12.5 ppm8.20 ppm2.5 ppm3.5 ppm5.2 ppm ppm Fig. (1): The 1 H-NMR spectrum of the ligand (L)
Hc =NCOOHAromatic carbons 159 ppm170 ppm ppm Table (2b): 13 C-NMR Chemical Shifts for Ligand (L) ( ppm in D 2 O) Fig. (2): The 13 C-NMR spectrum of the ligand (L)
Table (3): Infrared spectral data (wave number – ) cm –1 for the ligand and precursors symm. COO – assm. COO – (C=O) (C-H) Aromatic (C=N) (NH 2 ) (OH) Compound Glyoxylicacid o-phenylenc diamine L=C 10 H 8 N 2 O 4 Fig. (3): The IR spectrum of the ligand (L)
Table (4): Electronic spectral data of the Ligand (L) Assignments ( max molar –1 cm –1 ) – wave number cm –1 nm Compound n * * L=C 10 H 8 N 2 O 4 Fig. (4): Electronic spectrum of the ligand (L)
2. Synthesis of complexes
Solubility Found (Calc.) % effect Colour M.P. C Yield % Empirical formula metalNHC Water, methanol, ethanol, cetone DMF, DMSO (18.20) (9.21) 8.94 (3.61) 3.19 (37.61) Dark green 17090] [LCo.2H 2 O = (18.31) 18.84) (8.91) 8.94 (3.61) 3.19 (37.63) Pale brown 120 D 92[LNi.2H 2 O] = (30.11) (7.62) 7.65 (2.09) 2.73 (36.84) Redish brown 15088[LCu].3H 2 O = (30.11) (7.62) 7.65 (2.09) 2.73 (32.00) Pale brown 240D 80[LCd.2H 2 O] = (44.80) (6.76) 6.16 (2.25) 2.20 (26.68) Pale brown 14082[LHg.2H 2 O] = (44.20) (6.61) 6.07 (1.86) 1.30 (25.71) Pale brown 23085[LPb.2H 2 O] Table (5): The physical properties for complexes
M-OM-N Coordinate water cm –1 symm. COO – assm. COO – (C=O) (C-H) Aromatic (C=N) (OH) Compound [LCo.2H 2 O] [LNi.2H 2 O] [LCu].3H 2 O [LCd.2H 2 O] [LHg.2H 2 O] [LPb.2H 2 O] Table (6): Infrared spectral data (wave number – ) cm –1 for complexes
Fig. (5): The IR spectrum of the [LNi.2H 2 O] complex Table (7): Electronic spectral data for complexes Proposed structure Assignments ( max molar –1 cm –1 ) – wave number cm –1 nm Compound Octahedral 4 T 1 g (P) 4 T 1 g [LCo.2H 2 O] Octahedral 3 T 1 g (F) 3 A 2 g (F) 3 T 1 g (P) 3 A 2 g (F) [LNi.2H 2 O] Square planar 2 A 1 g 2 B 1 g 2 Eg 2 B 1 g [LCu].3H 2 O OctahedralC. T [LCd.2H 2 O] OctahedralC. T [LHg.2H 2 O] OctahedralC. T [LPb.2H 2 O]
Fig. (6): Electronic spectrum of the [LCo.2H 2 O] complex
Solutions chemistry Molar ratio as in Fig. (7): Fig. (7): The mole ratio curve of complex [LCu].3H 2 O in solution (1×10 -3 mole. L -1 ) at ( =272.8 nm)
Table (8): stability constant and G for the Ligand (L) complexes GG 1/KLog KK AmAsCompounds – × [LCu].3H 2 O – × [LCd.2H 2 O] Table (9): The molar conductance of the complexes ratio m S.cm 2 molar –1 Compound fragmentations 1:1160[LCo.2H 2 O] 1:1180[LNi.2H 2 O] 1:1130[LCu].3H 2 O 1:1170[LCd.2H 2 O] 1:1135[LHg.2H 2 O] 1:1180[LPb.2H 2 O] Molar conductivity for the complexes of the ligand (L)
Conclusion The new Schiff (L) and metal complexes where prepared [LCo.2H 2 O], [LNi.2H 2 O], [LCu].3H 2 O. [LCd.2H 2 O], [LHg.2H 2 O] and [LPb.2H 2 O]. The metal (II) ions are coordinated by two carboxylate –O atoms and two imine (H C= N) atoms. Spectroscopic, structurical and magnetic data show that all complexes are six-coordinate metal complexes owing to the ligation of tetradentate Schiff base moieties with two coordinated water except [LCu].3H 2 O showed square planar geometry as fellow: (Octahedral) (Square planar)