Synthesis, spectroscopic characterization, crystal structure and theoretical investigation of two azo-palladium (II) complexes derived from substituted (1-phenylazo)-2-naphtol

Abstract

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Preparation and Spectroscopic Studies of Cadmium(II), Zinc(II),Mercury(II) and Vanadium(IV) Chelates Azo Ligand Derived from 4-Methyl-7-hydroxycoumarin

“…The mass spectrum of azo-dye ligand showed peak at molecular ion m/e = 310 which indicates the unstable molecular weight of the expected C 17 H 14 N 2 O 4 formula due to losing methoxy and methyl groups in the gas-phase of GC conditions for the MS spectra then confirms formation of the azo dye [13]. The peaks observed at around m/e = 116 and 89 would be resulted from cleavage of chromen ring and points of -CH 3 and -OH respectively [12]. As well as the mass spectrum of vanadium (II) complex shows weak intensity peak at 747 that is allocated to the molecular ion of complex in the gas phase [14,17].…”

“…The broad absorption at 3500 cm -1 is assigned to -OH of coumarin azo ligand. The strong band at 1651 is associated to -C=O of chromene ring while the strong band at 1623 cm -1 is associated with -CH=CHof aromatic and -rings respectively [12,15] as given in Fig. 3.…”

“…The 13 C-NMR spectrum of azo ligand showed multiple peaks at 75 ppm related to -CH3 aliphatic carbon atom and 96 ppm related to -C=OH moiety [12][13]. The peaks at 125-135 ppm may be related to resonance of aromatic carbon atoms while the deshielded -C-N=N-and -C=C-of coumarin may be assigned to effect of withdrawing groups and showed at 145-165 ppm, respectively.…”

“…The peak showed at around δ (14.50) ppm was also recorded in the ligand spectrum, due to the -OH proton that is directly attached to C7 of chromen ring. The doublet of doublet peaks at around δ (12.45) ppm reflects mainly the spin coupling of aromatic protons adjacent to each other in aromatic substituted [12][13]. Furthermore, the aliphatic protons of -CH 3 groups attached at C-4 were resonated at around 4.43.…”

“…Recently the researchers have encouraged enhancing the electronic and geometrical features of complexes of azo dyes that they would have exhibited nonlinear optical elements and printing systems [11][12][13][14]. All the above mentioned about the development of coumarin azo dyes with their chelation ability afford us to prepare and characterize new azo dye complexes of Zn(II), Cd(II), V(IV) and Hg(II) derived from (E)-7hydroxy-6-((4-methoxyphenyl)diazenyl)-4-methyl-2Hchromen-2-one.…”