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The modularity and ease of synthesis of carbene-metal-amide (CMA) complexes based on the coinage metals (Au, Ag, Cu) and N-heterocyclic carbenes (NHCs) as ancillary ligands pave the way for the expansion of their applications beyond photochemistry and catalysis. Herein, we further improve the synthesis of such compounds by circumventing the use of toxic organic solvents which were previously required for their purification, and we expand their scope to include complexes incorporating carbolines as the amido fragments. The novel complexes are screened both in vitro and ex vivo, against several cancer cell lines and high-grade serous ovarian cancer (HGSOC) tumoroids, respectively. Excellent cytotoxicity values are obtained for most complexes, while the structural variety of the CMA library screened thus far, provides promising leads for future developments. Variations of all three components (NHC, metal, amido ligand), enable the establishment of trends regarding cytotoxicity and selectivity towards cancerous over normal cells.

Manganese(II) tetrahedral complexes having general formula [MnX2L2] (X = Cl, Br, I; L = 1,3-dimethyl-2- phenyl-1,3-diazaphospholidine-2-oxide) were isolated and characterized. The structures of the chloroand bromo-derivatives were ascertained by single-crystal X-ray diffraction. The three species are appreciably luminescent in the green region upon excitation with UV light. The luminescence lifetimes are strongly dependent upon the choice of the coordinated halide. The rigid 1,3-diazaphospholidine-2- oxide moiety improved the photoluminescence features with respect to comparable phenylphosphonic diamide Mn(II) derivatives.

While ruthenium arene complexes have been widely investigated for their medicinal potential, studies on homologous compounds containing a tridentate tris(1-pyrazolyl)methane ligand are almost absent in the literature. Ruthenium(II) complex 1 was obtained by a modified reported procedure; then, the reactions with a series of organic molecules (L) in boiling alcohol afforded novel complexes 2-9 in 77-99% yields. Products 2-9 were fully structurally characterized. They are appreciably soluble in water, where they undergo partial chloride/water exchange. The antiproliferative activity was determined using a panel of human cancer cell lines and a noncancerous one, evidencing promising potency of 1, 7, and 8 and significant selectivity toward cancer cells. The tested compounds effectively accumulate in cancer cells, and mitochondria represent a significant target of biological action. Most notably, data provide convincing evidence that the mechanism of biological action is mediated by the inhibiting of mitochondrial calcium intake.

The reaction of N,N,N’,N’-tetramethyl-P-indol-1-ylphosphonic diamide (L) with Mn(II) halides under mild conditions allowed the isolation of tetrahedral neutral complexes having the general formula [MnX2L2] (X = Cl, Br, I). The structures of the new coordination compounds were ascertained by single-crystal X-ray diffraction. The three species exhibited noticeable luminescence in the green region upon excitation with UV light, with emissions related to the Mn(II) 4T1(4G) → 6A1(6S) transition, without appreciable luminescence from the coordinated ligands. Luminescence was caused by both metal and ligand excitations. The good light harvesting features of the indol-1-yl fragment allowed the luminescence enhancement with respect to comparable phenyl-substituted derivatives.