A series of novel ruthenium(II) arene RAPTA type derivatives (arene = cymene, hexamethylbenzene) containing curcumin-based ligands (curcH = curcumin, bdcurcH = bisdemethoxycurcumin) and PTA (1,3,5-triaza-7-phosphaadamantane) have been synthesized and fully characterized. The solid-state structures of [Ru(cym)(curc)(PTA)][SO3CF3], [Ru(hmb)(curc)(PTA)][SO3CF3], and [Ru(hmb)(bdcurc)(PTA)][SO3CF3] have been determined by single-crystal X-ray diffraction. The antitumor activity of the complexes has been evaluated in vitro against human ovarian carcinoma cells (A2780 and A2780cisR), as well as against nontumorous human embryonic kidney (HEK293) cells. The correlation of the cytotoxicity upon switching the curcumin-based ligands, i.e. curcumin vs bisdemethoxycurcumin, is not straightforward. In contrast, the PTA ligand greatly enhances the activity and selectivity of ruthenium compounds in comparison to previously reported compounds

Three new flexidentate 5-substituted salicylaldimino Schiff base ligands (L1-OH-L3-OH) based on 1-(2-aminoethyl)piperazine (X=H, L1-OH; X=NO2, L2-OH; and X=Br, L3-OH) and their nickel(II) complexes (1a, 1b, 2, and 3) have been reported. The piperazinyl arm of these ligands can in principle have both boat and chair conformations that allow the ligands to bind the Ni(II) center in an ambidentate manner, forming square-planar and/or octahedral complexes. The nature of substitution in the salicylaldehyde aromatic ring and the type of associated anion in the complexes have profound influences on the coordination geometry of the isolated products. With the parent ligand L1-OH, the product obtained is either a planar red compound [Ni(L1-O)]+, isolated as tetraphenylborate salt (1a), or an octahedral green compound [Ni(L1-NH)(H2O)3](2+), isolated with sulfate anion (1b); both have been crystallographically characterized. In aqueous solution, both these planar (S=0) and octahedral (S=1) forms are in equilibrium that has been followed in the temperature range 298-338 K by 1H NMR technique using the protocol of Evans's method. The large exothermicity of the equilibrium process [Ni(L1-O)]+ + 3H2O + H+<=>[Ni(L1-NH)(H2O)3](2+) (DeltaH degrees=-46 +/- 0.2 kJ mol(-1) and DeltaS degrees=-133 +/- 5 J K(-1) mol(-1)) reflects formation of three new Ni-OH2 bonds in going from planar to the octahedral species. With the 5-nitro derivative ligand L2-OH, the sole product is an octahedral compound 2, isolated as a sulfate salt while with the bromo derivative ligand L3-OH, the exclusive product is a planar molecule 3 with associated tetraphenylborate anion. Both 2 and 3 have been structurally characterized by X-ray diffraction analysis.

Carboxamide based gelator molecule used for the detection of iron by turning off the aggregate-induced emission and selective sensing anion by either switching off or switching on the emission property of the metallogel.