Ring size effect on the solid state assembly of propargyl substituted hexa- and octacyclic peptoids

The investigation of the solid state assembly of propargyl substituted hexa- and octacyclic peptoids highlights the effect of ring size in determining the packing arrangement of the macrocycles. A layered arrangement is obtained in the case of the hexacyclic peptoid 1 and a tubular arrangement in the case of the octacyclic peptoid 2. Guest molecules either intercalate between the layers as in 1 or are located within the peptoid nanotube as in 2

N,N′-bis[(3-hydroxy-4(4H)-oxypyran-2-yl)methyl]-N,N′-dimethylethylene-1,2-diammonium tetrachloridoplatinate(II) dihydrate

The title compound (C16H22N2O 6)[PtCl4]·2H2O, shows antiproliferative activity in eight tumor cell lines. The asymmetric unit consists of one solvent water molecule on a general position, and one half of each of the polyammonium cation and the tetrachloridoplatinate(II) anion, both of them located on centers of inversion. In the crystal, the cations are connected via hydrogen bonding between the carbonyl O atoms and the hydroxyl H atoms into zigzag chains that elongate in the c-axis direction. In addition, the carbonyl O atom is hydrogen-bonded to the water molecule which, in turn, interacts with the [PtCl4]2- anion. Finally, the chains are linked by N-H +⋯Cl interactions into a three-dimensional network

2,5-Bis[2-({bis[3-(dimethylazaniumyl)propyl]azaniumyl}methyl)phenyl]-1,3,4-oxadiazole hexakis(perchlorate) sesquihydrate

none5noIn the title hydrated salt, C36H66N8O6+·6ClO4 -·1.5H2O, the asymmetric unit consists of a hexaprotonated [H6 L]6+ cation, five perchlorate anions in general positions, two on twofold rotation axes (one of which is disordered), and two water molecules of crystallization in general positions, one of them disordered around a twofold crystallographic axis. In the [H6 L]6+ cation, two strong intramolecular N-H⋯N hydrogen bonds occur, involving the N atoms of the oxadiazole ring as acceptors and the closest NH+ groups of each dipropylenetriamine unit. In the crystal, the [H6 L]6+ cations form channels along the a-axis direction, in which the perchlorate counter-ions and the water molecules are lodged. The crystal packing features a network of N-H⋯O and O-H⋯O hydrogen bonds involving the NH+ groups of the [H6 L]6+ cation, the perchlorate anions and the water molecules.mixedVieri Fusi; Mauro Formica; Eleonora Macedi; Paola Paoli; Patrizia RossiFusi, Vieri; Formica, Mauro; Macedi, Eleonora; Paola, Paoli; Patrizia, Ross

Solid-State Conformational Flexibility at Work: Energetic Landscape of a Single Crystal-to-Single Crystal Transformation in a Cyclic Hexapeptoid

We describe the energetic landscape beyond the solid-state dynamic behavior of a cyclic hexapeptoid decorated with four propargyl and two methoxyethyl side chains, namely, cyclo-(Nme-Npa2)2, Nme = N-(methoxyethyl)glycine, Npa = N-(propargyl)glycine. By increasing the temperature above 40 °C, the acetonitrile solvate form 1A starts to release acetonitrile molecules and undergoes a reversible single crystal-to-single crystal transformation into crystal form 1B with a remarkable conformational change in the macrocycle: two propargyl side chains move by 113° to form an unprecedented "CH-π zipper". Then, upon acetonitrile adsorption, the "CH-π zipper" opens and the crystal form 1B transforms back to 1A. By conformational energy and lattice energy calculations, we demonstrate that the dramatic side-chain movement is a peculiar feature of the solid-state assembly and is determined by a backbone conformational change that leads to stabilizing CH···OC backbone-to-backbone interactions tightening the framework upon acetonitrile release. Weak interactions as CH···OC and CH-π bonds with the guest molecules are able to reverse the transformation, providing the energy contribution to unzip the framework. We believe that the underlined mechanism could be used as a model system to understand how external stimuli (as temperature, humidity, or volatile compounds) could determine conformational changes in the solid state

Crystal structure of the BaII-based CoII-containing one-dimensional coordination polymer poly[[aquaμ4-2,2'-[(4,10-dimethyl-1,4,7,10-tetra-aza-cyclo-dodecane-1,7-di-yl)bis(methylidene)]bis-(4-oxo-4H-pyran-3-olato)-perchloratocobaltbarium] perchlorate]

The title compound, [BaCo(H-2L1)(ClO4)(H2O)]ClO4 n ,L1 =4,10-bis-[(3-hy-droxy-4-pyron-2-yl)meth-yl]-1,7-dimethyl-1,4,7,10-tetra-aza-cyclo-dodeca-ne, is a one-dimensional coordination polymer. The asymmetric unit consists of a Ba[Co(H-2L1)](ClO4)(H2O)+cationic fragment and a non-coordinating ClO4-anion. In the neutral [Co(H-2L1)] moiety, the cobalt ion is hexa-coordinated in a trigonal-prismatic fashion by the surrounding N4O2donor set. The Ba2+ion is nine-coordinated and exhibits a distorted [BaO9] monocapped square-anti-prismatic geometry, the six oxygen atoms coming from three distinct [Co(H-2L1)] moieties, while the remaining three vertices are occupied by the oxygen atoms of a bidentate perchlorate anion and a water mol-ecule. A barium-μ2-oxygen motif develops along theaaxis, connecting symmetry-related dinuclear BaII-CoIIcationic fragments in a wave-like chain, forming a one-dimensional metal coordination polymer. Non-coordinating ClO4-anions are located in the space between the chains. Weak C-H⋯O hydrogen bonds involving both coordinating and non-coordinating perchlorate anions build the whole crystal architecture. To our knowledge, this is the first example of a macrocyclic ligand forming a BaII-based one-dimensional coordination polymer, containing CoIIions surrounded by a N4O2donor set

Crystal structure of bis-μ2-2,2'-[(4,10-dimethyl-1,4,7,10-tetra-aza-cyclo-dodecane-1,7-di-yl)bis(meth-yl-ene)]bis-(4-oxo-4H-pyran-3-olato)dicobalt-calcium bis-(perchlorate) 1.36-hydrate

The title compound, [CaCo2(C22H30N4O6)2](ClO4)2·1.36H2O or Ca[Co(H-2L1)]2·2ClO4·1.36H2O whereL1is 4,10-bis-[(3-hy-droxy-4-pyron-2-yl)meth-yl]-1,7-dimethyl-1,4,7,10-tetra-aza-cyclo-dodecane, is a trinuclear complex whose asymmetric unit comprises a quarter of the Ca[Co(H-2L1)]22+trinuclear complex, half of a perchlorate ion and 0.34-water mol-ecules. In the neutral [Co(H-2L1)] moiety, the cobalt ion is hexa-coordinated in a trigonal-prismatic fashion by the surrounding N4O2donor set. A Ca2+cation holds together two neutral [Co(H-2L1)] moieties and is octa-coordinated in a distorted trigonal-dodeca-hedral fashion by the surrounding O atoms belonging to the deprotonated oxide and carbonyl groups of two [Co(H-2L1)] units. The coordination of the CoIIcation preorganizesL1and an electron-rich area forms, which is able to host hard metal ions. The comparison between the present structure and the previously published ones suggests a high versatility of this ligand; indeed, hard metal ions with different nature and dimensions lead to complexes having different stoichiometry (mono- and dinuclear monomers and trinuclear dimers) or even a polymeric structure. The heterotrinuclear CoII-CaII-CoIIcomplexes are connected in three dimensionsviaweak C-H⋯O hydrogen bonds, which are also responsible for the inter-actions with the perchlorate anions and the lattice water mol-ecules. The perchlorate anion is disordered about a twofold rotation axis and was refined giving the two positions a fixed occupancy factor of 0.5. The crystal studied was refined as a two-component inversion twin [BASF parameter = 0.14 (4)]