Synthesis, physico-chemical characterization and thermal behavior of new complexes with N4O2 donor set

In vitro antimicrobial activity and cytotoxicity of nickel(II) complexes with different diamine ligands

“…As was previously found, this shoulder arises from a spin forbidden triplet-to-singlet transition, 3 A 2g → 1 E g (D). 24,25 As could be seen from Fig. 1, the absorption maxima of the bands I and III for the investigated nickel(II) complexes were slightly shifted to higher energy in the following order 1 > 3 > 2.…”

“…The shape of the UV-Vis spectra for the investigated complexes was similar to that of the octahedral [Ni(en) 2 (H 2 O) 2 ]CO 3 complex (en is bidentately coordinated ethylenediamine) with the same N 4 O 2 coordination environment. 24 In accordance with the previously established results for the [Ni(en) 2 (H 2 O) 2 ]CO 3 complex, 24 the interpretation of UV-Vis spectra of the presently investigated complexes 1-3 was realized using an octahedral model (O h ): 3 A 2g → 3 T 2g (F) (band I), 3 A 2g → 3 T 1g (F) (band III) and 3 A 2g → 3 T 1g (P) (band IV). In addition, in each spectrum, there was a shoulder at approximately 735 nm (band II, Table I), which occurs on the higher-energy side of the spin allowed band I.…”

“…Moreover, all absorption maxima of the investigated complexes 1-3 were shifted to lower energies with respect to those for the [Ni(en) 2 (H 2 O) 2 ] 2+ complex. 24 This shifting results from the presence of a six-membered 1,3-propanediamine ring in 1-3, which is less strained than the five-membered ethylenediamine ring in the [Ni(en) 2 (H 2 O) 2 ] 2+ complex. The IR spectroscopic data for the nickel(II) complexes are listed in the Supplementary material to this paper and are consistent with the structural formula presented in Scheme 1.…”

“…Electronic absorption data for the nickel(II) complexes 1-3. For comparison the corresponding data for the previously reported [Ni(en) 2 (H 2 O) 2 ]CO 3 complex is given24 …”