Controlled Halogen-Bond-Involving Assembly of Double-sigma-Hole-Donating Diaryliodonium Cations and Ditopic Arene Sulfonates

The supramolecular dimensionality of halogen bonded architectures formed in the solid state by diaryliodonium salts is greater when the anion is a disulfonate rather than a monosulfonate. Specifically, diaryliodonium cations conventionally function as double-sigma-hole halogen bond (XB) donors and form 0D-heterotetrameric motifs when paired with monosulfonate anions. Here it is reported that when 1,5- and 2,6-naphthalenedisulfonate anions are used as ditopic XB acceptors, their assemblies with diaryliodonium cations provide architectures of higher dimensionality. 1,5-Naphthalenedisulfonate leads to the occurrence of 1D chains, while the longer and less sterically encumbered 2,6-naphthalenedisulfonate produces either 1D chains or 2D layers. The two-center I center dot center dot center dot OSO supramolecular synthon is observed most frequently, and the three-center I center dot center dot center dot OSO linkage was identified in some assemblies based on 2,6-naphthalenedisulfonate

Benzothienoiodolium Cations Doubly Bonded to Anions via Halogen-Chalcogen and Halogen-Hydrogen Supramolecular Synthons

The simultaneous binding of a molecular entity through two interactions is a frequently pursued recognition mode due to the advantages it offers in securing molecular self-assembly. Here, we report how the planarity of the benzothienoiodolium (BTI) cation allows for preorganizing in the cation plane the hydrogen, halogen, and chalcogen bonds (HBs, XBs, and ChBs, respectively) formed by the phenyl hydrogen, iodolium iodine, and thienyl sulfur. Crystallographic analyses of some BTI salts show how this interaction coplanarity enables their coupling to point toward a single anion that is coordinated via the supramolecular and heteroditopic synthon XB/HB or XB/ChB, the latter observed here for the first time. These synthons adopt a Janus-like arrangement around iodine. Crystallographic information suggests that interactions of the synthons act synergistically, e.g., when resulting in the unusually short ChBs formed by the thienyl sulfur. Determination of the molecular electrostatic potential, Bader's quantum theory of "atoms-in-molecules" analysis, and natural bond orbital investigations give information on the nature and energetic aspects of the short contacts observed in crystals

Synthesis of Cisplatin Analogues: Cytotoxic Efficacy and Anti-tumour Activity of Bis-Amidine and Bis-Iminoether Pt(II) Complexes

A series of new platinum(Il) bis-amidine derivatives were prepared by addition of primary and secondary aliphatic amines to coordinated nitrile ligands in cis- and trans-[PtCl2(NCR)2] (R = Me, Ph, CH2Ph). The bis-amidine complexes were tested for their in vitro cytotoxicity on a panel of various human cancer cell lines. The results indicated that the trans isomers are more effective than the cis species, and in particular the benzamidine complex trans-[PtCl2{E-N(H)=C(NMe2)Ph}2] was the most active derivative and was able to circumvent acquired cisplatin resistance, thus suggesting a different mechanism of action compared to that exhibited by cisplatin. New benzyliminoether derivatives cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2Ph}2] were also prepared by addition of MeOH to cis- and trans-[PtCl2(NCCH2Ph)2] and the cytotoxic properties were evaluated in terms of cell growth inhibition against a panel of different types of human cancer cell lines. The complex cis-[PtCI2{E-N(H)=C(OMe)CH2Ph}2] was significantly more potent than cisplatin against all tumour cell lines, including cisplatin-resistant ones. Moreover, the in vivo studies, performed on two transplantable tumour models, showed that cis-[PtCl2{E-N(H)=C(OMe)CH2Ph}2] exhibited a marked activity against murine L1210 leukaemia and Lewis lung carcinoma in terms of survival prolongation and tumour growth inhibition, respectively