Synthesis And Properties Of Containing A Pyridine Ring Lariat Crown Ether Complexes

N-Pivot lariat ethers are well known to have strong coordination ability for alkali and alkaline earth ions and to have excellent coordination ability for transition metal ions or ammonium ions. Therefore, N-Pivot lariat ethers have received much attention as receptors. For further investigation in this field, in this paper, we synthesized a series of new N-Pivot lariat ethers compounds containing pyridine ring and their transition mental ion complexes. All of the aza-crown lariat ethers and their complexes were characterized by EA, IR, UV, ¹H NMR,¹³C NMR.1. Six kinds of new N-Pivot lariat ethers were prepared by using the 2-methyl pyridine, diethanolamine, salicylaldehyde, diamine as materials. The syntheses of the new kinds of aza-crown lariat ethers (L₁-L₆) are shown as follows:NH2RNH2 NaBH4NNHHN R(L,-L6)R=CH2CH2R=CH2CH2CH2R=CH2(CH2)2CH2R=CH2(CH2)4CH2R=CH2CH2NHCH2CH2R=CH2CH2NHCH2CH2NHCH2CH2N-(2-pyridylmethyl)diethanolamine (V) was obtained by the reaction of 2-(chloromethyl)pyridine with diethanolamine. The reaction of V with /?-toluene-sulfonyl chloride gave N-(2-pyridylmethyl)diethanoIamine di(p-toluenesulfonate) (VI). Dialdehyde (W) was prepared by the reaction of VI with salicylaldehyde in the presence of anhydrous K2CO3 in N,N-dimethylformide. In the syntheses of L1-L6, the dialdehyde (VH) was condensed with different diamines in the mixture solution of methanol and trichloromethane. The corresponding Schiff-base derivatives were not isolated, but instead of reduction which was carried out by slow addition of sodium borohydride to the reaction mixture. It is not necessary to carry out the ring closure step either under high dilution conditions or in the presence of template ions.Furthermore, a new Schiff-base type macrocycle compound L7 was prepared by the reaction of dialdehyde (Vfl) with 1,3-phenylenediamine. In the syntheses of L4, a Schiff-base derivative Lg was also isolated.The structures proposed for the new macrocycles are consistent with the data obtained from their EA, IR, UV, lH NMR, 13C NMR.2. Nineteen complexes of the aza-crown lariat ethers (Li-L,6) with transition metal chlorides (CdCh, C0CI2, NiCk, CuCb) were prepared and characterized by EA, IR, UV and molar conductivity. The compositions of the complexes can be defined as MLC12 ? nH2O (M=Cd, Co, Ni, Cu, L=LrL6, n=0-6).By contrasting the IR spectra of aza-crown lariat ethers and complexes, it was found that the vibration absorption of C-O-C, C-N and pyridine ring had obvious shifts. The UV spectra of the ligands and metal complexes show that the maximal absorption wavelengths also had obvious shifts. These results denote that the oxygen and nitrogen atoms in the aza-crown lariat ethers coordinate with the transition metal ions. The molar conductance values indicate that the complexes of aza-crown lariat ethers with transition metal chlorides are electrolytes. These results show that one or neither of the two chloride anions coordinated to the metal ions.3. The transport of alkali metal ions (Na+ and KT) across a liquid membrane using the aza-crown lariat ethers (L1-L6) as ion-carriers was also studied. The results show that the observed transport rates of Na+ have the following order Li>L.2>L3>L6>L5>L4, on the other hand, the observed transport rates of K+ have the following order Li