Some Salicylato New Organotin (IV) and Copper Chloride Adducts and Derivative: Synthesis and Spectroscopic Study ()
1. Introduction
Several papers about carboxylate compounds have yet been published because of their coordinating ability [1]-[5]. For widening the data on coordinating ability of carboxylate summarized by Hathaway [6]. We have been, in this work, a MeOH or EtOH solution methylamine (MeNH2) with salicylic acid and SnPh3Cl or SnCl4 or CuCl2∙2H2O in a specific ratio. In this paper, we have initiated the study of the interactions between HOC6H4CO2H, MeNH2, SnPh3Cl or SnCl4 or CuCl2∙2H2O which has yielded three new complexes. These compounds have been studied using Infrared, 119Sn NMR and UV-visible techniques and structures suggested on the basis of spectroscopic data.
2. Materials and Methods
The compound 1 is obtained by a methanolic solution of MeNH2 with salicylic acid and SnPh3Cl in 2/2/1 ratio. The compounds 2 and 3 were obtained by mixing in ethanolic solution of MeNH2 with salicylic acid and SnCl4 (2) or CuCl2∙2H2O (3) in the ratio 1/1/1. All the mixtures gave limpid solution after three hours of reflux at 60˚C and have been submitted to a slow solvent evaporation. The analytical data allow to suggest the following formulae (Table 1).
Table 1. Suggested formulae of synthesized compounds and the elemental analyses.
Compound |
Chemical formulae |
Elemental analyses (%) |
C |
H |
N |
calc. |
found |
calc. |
found |
calc. |
found |
1 |
[HOC6H4CO2(SnPh3)] |
61.64 |
61.78 |
4.14 |
4.26 |
0.00 |
0.00 |
2 |
(MeNH3)[OHC6H4CO2(SnCl4)] |
18.85 |
18.94 |
2.18 |
2.16 |
2.75 |
2.56 |
3 |
(MeNH3)[OHC6H4CO2(CuCl2)]∙2H2O |
28.54 |
28.48 |
3.59 |
3.56 |
4.16 |
4.20 |
The elemental analyses have been obtained from the Institute of Molecular Chemistry of the University of Burgundy, Dijon-France. The 119Sn NMR spectra were performed at the Institute of Molecular Chemistry of the University of Burgundy, Dijon-France using a Bruker Avance 400 MHz Spectrometer with a low sensitivity band. The IR spectra of the compounds were recorded at room temperature using an FTIR spectrometer at the University Cheikh Anta Diop Dakar and at the Institute of Molecular Chemistry of the University of Burgundy, Dijon-France (over a range from 4500 to 400 cm−1) in the form of suspension of powders in Nujol or crushed dry. The UV-visible have been obtained from the spectrometer at the University Cheikh Anta Diop Dakar.
3. Results and Discussion
Let us consider the IR, 119Sn NMR and UV-visible data.
IR (cm−1): 1: ν (OH) = 3250 (br); νas (COO−) = 1651 (m), 1585 (m); νs (COO−) = 1472 (s), 1383 (vs); δ (COO−) = 865 (w), 852 (m); νas (SnPh3) = 727 (vs), 692 (vs) 2: ν (NH) = 2935 (br); ν (OH) = 3213 (br); δ (NH) = 1524 (vs); νas (COO−) = 1651 (m), 1585 (m); νs (COO−) = 1472 (s), 1383 (vs); δ (COO−) = 893 (s), 851 (s); ν (Sn-O) = 587 (m) 3: ν (NH) = 2935 (br); ν (OH) = 3229 (br); δ (NH) = 1440 (s); νas (COO−) = 1652 (s), 1481 (s); νs (COO−) = 1463 (m), 1384 (m); δ (COO−) = 887 (s), 851 (m); ν (Sn-O) = 603 (m) 119Sn NMR (CDCl3, ppm): 1: δ = −110.21 (s).
UV-visible (nm): 1: λmax = 298 (s)
2: λmax = 296 (s)
From these spectroscopic data, we suggest:
[HOC6H4CO2(SnPh3)] (1)
While considering the IR of the [HOC6H4CO2(SnPh3)] derivative, the doublet at 727 and 692 cm−1 attributed to phenyl vibrations confirming the presence of the SnPh3 residue. Several carboxylate bands appear, including the one at 1462 cm−1 strong confirms its presence. The broad band centered at 3350 cm−1 is attributed to the ν (OH) vibration. Through these IR data, the suggested structure is discret with the salicylate ligand is monochelating and the environment around the tin centre being tetrahedral (Figure 1).
Figure 1. Proposed structure for the compound 1.
On the 119Sn NMR spectrum, the only signal at −110 ppm indicates the presence of a single type of tetracoordinated tin in the structure. This value is characteristic of a tin atom with a tetrahedral environment as reported in the literature [7]. The only strong absorption at 298 nm attributed to 𝜋 → π∗ transitions based on the aromatic double bonds of the salicylate.
(MeNH3)[OHC6H4CO2(SnCl4)] (2)
The IR spectrum of the complex (MeNH3)[OHC6H4CO2(SnCl4)] shows several bands in the valence zone of the carboxylate, including the one at 1481 cm−1 which appears strong, confirming its presence. The existence of hydrogen bonds in compound 2 is explained by the presence of the broad band centered at 2935 cm−1 and the average one at 587 cm−1 to the Sn-O vibration [8]. Through these IR data, a discret structure reported in Figure 2 with a tin centre in an octahedral environment is suggested, the salicylate behaving as a monochelating ligand [9]. When the cation is involved through NH…Cl hydrogen bonds a supramolecular architecture may be obtained.
Figure 2. Proposed structure for the compound 2.
(MeNH3)[OHC6H4CO2(CuCl2)]∙2H2O (3)
While considering the IR of the (MeNH3)[OHC6H4CO2(CuCl2)]∙2H2O derivative, we note several bands in the valence zone of the carboxylate including the one at 1481 cm−1, which appears strong confirms its presence. The broad band centered at 2935 cm−1 is due to the presence of hydrogen bonds and the medium band at 603 cm−1 to the Cu-O vibration [9].
For 3 the suggested structures are discrete (Figure 3), the environment around the copper centre being tetrahedral and the salicylate behaving as a monochelating ligand. When the cation is involved through NH…Cl hydrogen bonds a supramolecular architecture may be obtained [10]. Water molecules are in a network.
Figure 3. Proposed structure for the compound 3.
For compound 3 the cation may interact via hydrogen bonds leading to a supramolecular architecture. For the compound 2, OH groups may also be involved in intermolecular hydrogen bonds leading to a supramolecular architecture.
4. Conclusion
The Three Adducts studied have discrete structures, with the anion behaving as a monodentate or monochelating ligand. The environments of the tin (IV) centres are trigonal bipyramidal or octahedral. In free OH or NH…Cl containing structures, when extra hydrogen bonds are considered, supramolecular architectures may be obtained. The environment around the tin centre is octahedral or tetrahedral and the environment around the copper centre is tetrahedral. When extra intermolecular hydrogen bonds are considered supramolecular architectures may be obtained.
Acknowledgements
We thank Laurent Plasseraud, ICMUB UMR CNRS 6302, University of Burgundy, Faculty of Sciences, Dijon, France.
List of Notations
IR abbreviations: Br (Broad); VS (Very Strong); S (Strong); M (Medium), W (Weak)