Identifying and characterizing new magnetic systems with Co2+ ions can enhance our understanding of quantum behavior since Co2+ can host a pseudospin-1/2 magnetic ground state. Understanding the magnetic ground state...

Three‐component reaction of 4‐hydroxy‐2H‐benzo[h]chromen‐2‐one, aromatic aldehydes, and malononitrile in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in ethanol at room temperature affords good yields of novel dihyrobenzo[h]pyrano[3,2‐c]chromene derivatives. The synthesized compounds examined by MTT assays for cytotoxic activity in two human cancer cell lines (MOLT‐4, HL‐60). Most of the evaluated compounds showed low inhibitory activity against tumor cell line at micromolar concentrations.

The asymmetric unit of the title proton-transfer compound, C5H8N3 +·C7H4NO4 −, consists of one mono-deprotonated pyridine-2,6-dicarb­oxy­lic acid as anion and one protonated 2,3-diamino­pyridine as cation. The crystal packing shows extensive O—H⋯O, N—H⋯O and N—H⋯N hydrogen bonds. Thre are also several π–π inter­actions between the anions and also between the cations [centriod–centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å].

The asymmetric unit of the title proton-transfer compound, C5H16N2 2+·2C7H4NO4 −·H2O, consists of two mono-deproton­ated pyridine-2,6-dicarb­oxy­lic acid mol­ecules as anions, viz. (py-2,6-dcH)−, one diprotonated N 1,N 1-dimethyl­propane-1,2-diamine mol­ecule as a cation, viz. (dmpdaH2)2+, and one water mol­ecule. The crystal packing shows extensive O—H⋯O, N—H⋯O, N—H⋯N and O—H⋯N and weak inter­molecular C—H⋯O hydrogen bonds. These inter­actions link the (dmpdaH2)2+ cation, the (py-2,6-dcH)− anions and water mol­ecule and play an important role in the stabilization of crystal packing.

Key indicators: single-crystal X-ray study; T = 120 K; mean (C-C) = 0.003 Å; disorder in main residue; R factor = 0.063; wR factor = 0.136; data-to-parameter ratio = 21.5.In the title compound, 2C 12 H 24 N + ÁC 6 H 6 O 7 2À ÁC 2 H 6 O, the cyclohexane rings of the cations adopt chair conformations. In the anion, intramolecular O-HÁ Á ÁO hydrogen bonds occur. In the crystal, the cations link with the anions via N-HÁ Á ÁO hydrogen bonds. Weak C-HÁ Á ÁO hydrogen bonds are also observed. The hydroxy group of the ethanol solvent molecule is disordered over two sets of sites with an occupancy ratio of 0.766 (5):0.234 (5). Related literature ExperimentalCrystal data