2,4 -Dimethoxybenzoates of Mn(II), Co(II) and Cu(II) have been synthesized as hydrated or anyhydrous polycrystalline solids and characterized by elemental analysis, IR spectroscopy, magnetic studies and X-ray diffraction measurements. They possess the following colours: Mn(II) -white, Co(II) -pink and Cu(II) -blue. The carboxylate groups bind as monodentate, or a symmetrical bidentate bridging ligands and tridentate. The thermal stabilities were determined in air at 293-1173K. When heated the hydrated complexes dehydrate to from anhydous salts which are decomposed to the oxides of respective metals. The magnetic susceptibilites of the 2,4-dimethoxybenzoates were measured over the range 76-303 K and their magnetic moments were calculated. The results reveal the complexes of Mn(II), Co(II) to be high-spin complexes and that of Cu(II) to form dimer.

Physico-chemical properties of 3,4-dimethoxybenzoates of Co(II), Cu(II), La(III) and Nd(III) were studied. The complexes were obtained as hydrated or anhydrous polycrystalline solids with a metal ion-ligand mole ratio of 1 : 2 for divalent ions and of 1 : 3 in the case of trivalent cations. Their colours depend on the kind of central ion: pink for Co(II) complex, blue for Cu(II), white for La(III) and violet for Nd(III) complexes. The carboxylate groups in these compounds are monodentate, bidentate bridging or chelating and tridentate ligands. Their thermal decomposition was studied in the range of 293-1173 K. Hydrated complexes lose crystallization water molecules in one step and form anhydrous compounds, that next decompose to the oxides of respective metals. 3,4 -Dimethoxybenzoates of Co(II) is directly decomposed to the appropriate oxide and that of Nd(III) is also ultimately decomposed to its oxide but with the intemediate formation of Nd 2 O 2 CO 3. . The magnetic moment values of 3,4-dimethoxybenzoates determined in the range of 76-303 K change from 4.22 µ B to 4.61 µ B for Co(II) complex , from 0.49 µ B to 1.17 µ B for Cu(II) complex , and from 2.69 µ B to 3.15 µ B for Nd(III) complex.

The physicochemical properties of 2,4-, and 3,4-dimethoxybenzoates of Cu(II), Co(II) and Nd(III) were studied and compared to observe the-OCH 3 substituent positions in benzene ring on the character of complexes. The analysed compounds are crystalline hydrated or anhydrous salts with colours depending on the kind of central ions: blue for Cu(II), pink for Co(II) and violet for Nd(III) complexes. The carboxylate groups bind as monodentate, bidentate bridging or chelating and even tridentate ligands. Their thermal stabilities were studied in air at 293-1173K. When heated the hydrated complexes release the water molecules and form anhydrous compounds which are then decomposed to the oxides of respective metals. Their magnetic moment values were determined in the range of 76-303K. The results reveal the compounds of Nd(III) and Co(II) to be the high-spin and that of Cu(II) forms dimer. The various positions of-OCH 3 groups in benzene ring influence some of physicochemical properties of analysed compounds.

2,4 - Dimethoxybenzoates of Mn(II), Co(II) and Cu(II) have been synthesized as hydrated or anyhydrous polycrystalline solids and characterized by elemental analysis, IR spectroscopy, magnetic studies and X-ray diffraction measurements. They possess the following colours: Mn(II) – white, Co(II) – pink and Cu(II) – blue. The carboxylate groups bind as monodentate, or a symmetrical bidentate bridging ligands and tridentate. The thermal stabilities were determined in air at 293-1173K. When heated the hydratedcomplexes dehydrate to from anhydous salts which are decomposed to the oxides of respective metals. The magnetic susceptibilites of the 2,4-dimethoxybenzoates were measured over the range 76-303 K and their magnetic moments were calculated. The results reveal the complexes of Mn(II), Co(II) to be high-spin complexes and that of Cu(II) to form dimer.

The physicochemical properties of 2,4-, and 3,4-dimethoxybenzoates of Cu(II), Co(II) and Nd(III) were studied and compared to observe the -OCH3 substituent positions in benzene ring on the character of complexes. The analysed compounds are crystalline hydrated or anhydrous salts with colours depending on the kind of central ions: blue for Cu(II), pink for Co(II) and violet for Nd(III) complexes. The carboxylate groups bind as monodentate, bidentate bridging or chelating and even tridentate ligands. Their thermal stabilities were studied in air at 293-1173K. When heated the hydrated complexes release the water molecules and form anhydrous compounds which are then decomposed to the oxides of respective metals. Their magnetic moment values were determined in the range of 76-303K. The results reveal the compounds of Nd(III) and Co(II) to be the high-spin and that of Cu(II) forms dimer. The various positions of -OCH3 groups in benzene ring influence some of physicochemical properties of analysed compounds.