Mononuclear or Coordination Polymer Complexes? Both Are Possible for 3,6,9-Trioxaundecanedioic Acid.

Investigating the driving forces leading to the formation of a specific supramolecular architecture among a wide spectrum of all the possibly obtainable structures is not an easy task. The contemporary literature provides several models for correctly predicting the thermodynamically accessible structures that can originate from a library of building blocks. Definitions are rigid by their very nature, so their application may sometimes require a shift in perspective. In the study presented herein, we describe the crystal structures of three metallo-supramolecular architectures assembled from deprotonated derivatives of 3,6,9-trioxaundecanedioic acid and Mn(II), Co(II) and Zn(II). In the Mn(II) case, the complexation resulted in a complex of a discrete/heptacoordinated nature, whereas the other two structures appeared as helical polymers. To explain such an anomaly, in this work, we describe how the interplay between the flexibility of the ligand spacer and the number of coordinating atoms involved determines the divergent or convergent organisation of the final coordination architecture.

Do Secondary Electrostatic Interactions Influence Multiple Dihydrogen Bonds? AA-DD Array on an Amine-Borane Aza-Coronand: Theoretical Studies and Synthesis.

Hydrogen bond plays a key role in a wide range of inorganic, organic, as well as biological systems. The understanding on how the chemical environment can affect this kind of interaction is crucial to predict its binding strength and consequently the robustness and the dynamic properties of many supramolecular systems. In this paper a new donor-acceptor complex was synthesized and characterized by SCXRD, showing for the first time in an organic system an AA-DD pattern of a particular hydrogen interaction, called dihydrogen bond. Over 250 functionals were computationally evaluated to select the best method to reproduce the binding interaction geometry of this new pattern. Moreover, a new vector force model was used to split the contribution of primary and secondary electrostatic interactions (SEIs), in order to evaluate how the latter one can modify the binding strength of this unusual hydrogen-hydrogen interaction.

Intermolecular Forces Driving Hexamethylenetetramine Co-Crystal Formation, a DFT and XRD Analysis.

Interest in co-crystals formation has been constantly growing since their discovery, almost a century ago. Such success is due to the ability to tune the physical-chemical properties of the components in solid state by avoiding a change in their molecular structure. The properties influenced by the co-crystals formation range from an improvement of mechanical features and chemical stability to different solubility. In the scientific research area, the pharmacological field is undoubtedly one of those in which an expansion of the co-crystal knowledge can offer wide benefits. In this work, we described the crystalline structure of hexamethylenetetramine co-crystallized with the isophthalic acid, and we compared it with another co-crystal, showing the same components but different stoichiometry. To give a wider overview on the nature of the interactions behind the observed crystal packing and to rationalize the reasons of its formation, a computational analysis on such structures was carried out.

Identification of 2-thioxoimidazolidin-4-one derivatives as novel noncovalent proteasome and immunoproteasome inhibitors.

This paper describes the design, synthesis, and biological evaluation of 2-thioxoimidazolidin-4-one derivatives as inhibitors of proteasome and immunoproteasome, potential targets for the treatment of hematological malignancies. In particular, we focused our efforts on the design of noncovalent inhibitors, which might be a promising therapeutic option potentially devoid of drawbacks and side-effects related to irreversible inhibition. Among all the synthesized compounds, we identified a panel of active inhibitors with Ki values towards one or two chymotrypsin-like activities of proteasome (ß5c) and immunoproteasome (ß5i and ß1i subunits) in the low micromolar range. Docking studies suggested a unique binding mode of the molecules in the catalytic site of immunoproteasome proteolytic subunits.

Long-Term Results of Aortic Root Surgery in Marfan Syndrome Patients: A Single-Center Experience.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare long-term results of Marfan syndrome (MFS) patients affected by aortic root disease undergoing aortic root replacement with the Bentall or David operation. METHODS: Since 1994, a total of 59 patients has been followed at the authors' Marfan Center, having undergone either a Bentall operation (Bentall group, n = 30) or a David operation (David group, n = 29). RESULTS: No operative mortality was recorded. After 20 years (mean follow up 97 ± 82 months; range 1 to 369 months) no prosthesis-related major bleeding or thromboembolic events had been observed; the 20-year survival was 94 ± 6% in the Bentall group, and 100% in the David group (p = 0.32). Freedom from reintervention for aortic valve dysfunction was 100% in the Bentall group, and 75 ± 13% in the David group (p = 0.04). This inter-group difference became relevant after the first eight-year period of follow-up, and was mainly associated with a particular familiar genetic phenotype involving three out of four reoperated patients. Freedom from all-cause death, myocardial infarction, stroke, prosthetic valve-related complications, and reintervention on any aortic segment was 69 ± 12% in the Bentall group, and 67 ± 14% in the David group (p = 0.33). CONCLUSIONS: The Bentall and David operations are both associated with satisfactory long-term results in MFS patients. The low rate of valve prosthesis-related complications suggested that the Bentall operation would continue to be a standard surgical treatment. The reimplantation technique, adopted for less-dilated aortas, provides satisfactory freedom from reoperation. Careful attention should be paid to the reimplantation technique in patients affected by a serious familiar genetic phenotype.

Synthesis of spiro[isoindole-1,5'-isoxazolidin]-3(2H)-ones as potential inhibitors of the MDM2-p53 interaction.

A series of spiro[isoindole-1,5-isoxazolidin]-3(2H)-ones has been synthesized by 1,3-dipolar cycloaddition of N-benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9-22 µM. Biological tests suggest that the antitumor activity could be linked to the inhibition of the protein-protein p53-MDM2 interaction. Docking measurements support the biological data.

{2,6-Bis[(pyridin-2-yl)sulfanylmeth-yl]pyridine-κ(2) N,N'}(η(3)-prop-2-en-yl)palladium(II) hexa-fluoro-phosphate.

The title compound, [Pd(C3H5)(C17H15N3S2)]PF6, is built up by a [(η(3)-all-yl)Pd](2+) fragment coordinated by a 2,6-bis-[(pyridin-2-yl)sulfanylmeth-yl]pyridine ligand coordinated through the N atoms. One of the S atoms is at a close distance to the metal centeratom [3.2930 (8) Å]. The Pd(II) atom is tetra-coordinated in a strongly distorted square-planar environment mainly determined by the η(3)-allyl anion in which the central C atom is disordered over two equally occupied positions. The crystal packing is very compact and is characterized by a three-dimensional network of C-H⋯F interactions between the F atoms of each anion and several H atoms of the surrounding cationic complexes.

Synthesis, characterization, crystal structure, and biological studies of two new Cd (II) complexes with 4'-(4-chlorophenyl)-2,2' :6',2"-terpyridine (Clphtpy).

Two new Cd(II) complexes, with the ligand 4'-(4-chlorophenyl)-2,2':6',2"-terpyridine (Clphtpy) formulated as: [Cd(Clphtpy)(NO3)2H2O] (1), and [Cd(Clphtpy)(N3)2]2 (2), have been synthesized and characterized by CHN elemental analysis as well as FT-IR, 1H NMR, absorption and emission spectroscopy, thermal analysis and analyzed structurally by X-ray single-crystal diffraction. The single crystal X-ray analysis showed that the coordination number in complex 1 and 2 were seven and six with N3O4 and N6 coordination sphere, respectively. The antibacterial activities of the synthesized complexes were tested against four gram-positive and four gram-negative bacteria. A biological study of the complexes indicated that the complex 1 exhibited very good activity against most of the tested bacteria and its activity was better than gentamicin as a standard antibiotic.

Tetra-kis(µ-4-chloro-benzoato-κ(2) O:O')bis-[(ethanol-κO)copper(II)](Cu-Cu).

In the centrosymmetric dinuclear title Cu(II) complex, [Cu2(C7H4ClO2)(C2H5OH)2], the Cu-Cu distance is 2.5905 (4) Å. The two metal atoms are bridged by four 4-chloro-benzoate ligands and each has an ethanol mol-ecule in the axial position of the overall octahedral coordination environment. The crystal packing features O-H⋯O hydrogen bonds.

The bottle and the glass say to me: "pour!".

The present study aimed at determining whether the observation of two functionally compatible artefacts, that is which potentially concur in achieving a specific function, automatically activates a motor programme of interaction between the two objects. To this purpose, an interference paradigm was used during which an artefact (a bottle filled with orange juice), target of a reaching-grasping and lifting sequence, was presented alone or with a non-target object (distractor) of the same or different semantic category and functionally compatible or not. In experiment 1, the bottle was presented alone or with an artefact (a sphere), or a natural (an apple) distractor. In experiment 2, the bottle was presented with either the apple or a glass (an artefact) filled with orange juice, whereas in experiment 3, either an empty or a filled glass was presented. In the control experiment 4, we compared the kinematics of reaching-grasping and pouring with those of reaching-grasping and lifting. The kinematics of reach, grasp and lift was affected by distractor presentation. However, no difference was observed between two distractors that belonged to different semantic categories. In contrast, the presence of the empty rather filled glass affected the kinematics of the actual grasp. This suggests that an actually functional compatibility between target (the bottle) and distractor (the empty glass) was necessary to activate automatically a programme of interaction (i.e. pouring) between the two artefacts. This programme affected the programme actually executed (i.e. lifting). The results of the present study indicate that, in addition to affordances related to intrinsic object properties, "working affordances" related to a specific use of an artefact with another object can be activated on the basis of functional compatibility.

31-Benz-yloxy-5,11,17,23,29-penta-tert-butyl-calix[5]arene-32,33,34,35-tetra-ol.

The title compound, C62H76O5, known to be one of the most versatile synthetic precursors/inter-mediates of calix[5]arene derivatives, adopts an approximate Cs -symmetric cone-in conformation. The aryl-oxybenzyl ring is tilted in such a way that the p-tert-butyl group fills the macrocycle cavity, while the benzyl group moves away from the cavity axis. In the crystal, this conformational arrangement is secured by intra- and inter-molecular O-H⋯O hydrogen bonds forming inversion dimers. Four tert-butyl groups are disordered over two orientations, with occupancy ratios of 0.745 (6):0.255 (6), 0.837 (5):0.163 (5), 0.850 (5):0.150 (5) and 0.845 (8):0.155 (8).

5-Amino-3-methyl-1,2-oxazole-4-carbonitrile.

In the title compound, C(5)H(5)N(3)O, the isoxazole ring is essentially planar, with a maximum deviation of 0.007 (1) Šfrom the least-squares plane. The N atom of the amine group exhibits sp(2) character (sum of bond angles around this atom = 358°). In the crystal, mol-ecules are aggregated by two kinds of N-H⋯N hydrogen bonds into fused R(2) (2)(12) and R(6) (6)(26) rings, forming a slightly puckered two-dimensional array lying parallel to (101).

[(Pyridine-2,6-dicarboxyl-ato)copper(II)]-µ-(pyridine-2,6-dicarboxyl-ato)-[bis-(ethyl-enediamine)-copper(II)]-µ-(pyridine-2,6-dicarboxyl-ato)-[(pyridine-2,6-dicarboxyl-ato)copper(II)] ethyl-enediamine monosolvate tetra-hydrate.

The title compound, [Cu(3)(C(7)H(3)NO(4))(4)(C(2)H(8)N(2))(2)]·C(2)H(8)N(2)·4H(2)O, was obtained by the reaction of copper(II) acetate dihydrate with pyridine-2,6-dicarb-oxy-lic acid (H(2)dipic) and ethyl-enediamine (en) in an aqueous solution. All of the Cu(II) atoms in the trinuclear centrosymmetric title complex are six-coordinated in a distorted octa-hedral geometry with N(2)O(4) and N(4)O(2) environments for the outer and central Cu(II) atoms, respectively. Various inter-actions, including numerous O-H⋯O and C-H⋯O hydrogen bonds and C-O⋯π stacking of the pyridine and carboxyl-ate groups [O⋯centroid distances = 3.669 (2) and 3.668 (2) Å] are observed in the crystal structure.

Dianilinium bis-(pyridine-2,6-dicarboxyl-ato-κ(3)O(2),N,O(6))cuprate(II) hexa-hydrate.

The asymmetric unit of the title complex, (C(6)H(8)N)(2)[Cu(C(7)H(3)NO(4))(2)]·6H(2)O, contains half a copper(II)-dipicolinate complex located on a twofold rotation axis, one protonated aniline mol-ecule and three solvent water mol-ecules. The Cu(II) atom is coordinated by four O atoms and two N atoms from two dipicolinate ligands in a distorted octa-hedral environment. In the crystal, the components are linked into a three-dimensional framework by inter-molecular O-H⋯O and N-H⋯O inter-actions.

Allylpalladium dimers with metals connected by binucleating dithiooxamidates in two different coordination modes: solution behavior and solid-state structure.

A series of allylpalladium dimers having metals connected by binucleating dialkyldithiooxamidate [N(R)SC-CS(R)N](2-) [R = methyl, ethyl, isopropyl, benzyl, isoamyl, (S)-1-(1-phenyl)ethyl, meso-(1-phenyl)ethyl, and rac-(1-phenyl)ethyl] were prepared by reacting the monochelate [(η(3)-allyl)Pd(N(R)SC-CS(R)NH κ-S,S Pd)] with [(η(3)-allyl)PdCl](2) in chloroform. At low temperature (20 °C), the bimetallic complexes [(η(3)-allyl)Pd](2)(µ-dialkyldithiooxamidate κ-N,N' Pd, κ-S,S' Pd') (kinetic compounds) are formed in a short reaction time (10 min). At a higher temperature (50 °C) and a longer reaction time (24 h), the corresponding bimetallic isomers [(η(3)-allyl)Pd](2)(µ-dialkyldithiooxamidate κ-N,S Pd, κ-N',S' Pd') (thermodynamic compounds) are obtained. Both kinetic and thermodynamic compounds can exist as endo or exo isomers, depending on the reciprocal orientation of the allyl cuspids. Both endo and exo isomers are only detectable in solution when the alkyl substituents are chiral alkyl groups. Moreover, diffractometric modeling agrees with the presence of both isomers in the solid state even when the alkyl substituent is an achiral alkyl group. In a chloroform solution, endo and exo isomers undergo isomeric conversion owing to the apparent allyl rotation that follows the Pd-N bond rupture in the (η(3)-allyl)Pd(N^N) frame of kinetic compounds or in the (η(3)-allyl)Pd(N^S) frame of thermodynamic compounds. The dithiooxamidate [N(R)SC-CS(R)N](2-), when engaged in a κ-N,S Pd, κ-N',S' Pd' coordination mode, behaves as a hybrid hemilabile binucleating ligand. At room temperature and in a chloroform solution, the kinetic compounds rearrange into the thermodynamically more stable isomers in about 3 or 4 days. The higher stability of the thermodynamic species was evaluated by means of computational studies in accordance with the maximum hardness principle. Finally, the crystal structures of [(η(3)-allyl)Pd](2)(µ-diethyldithiooxamidate κ-N,S Pd, κ-N',S' Pd'), [(η(3)-allyl)Pd](2)(µ-meso-(1-phenyl)ethyldithiooxamidate κ-N,S Pd, κ-N',S' Pd'), and [(η(3)-allyl)Pd](2)(µ-rac-(1-phenyl)ethyldithiooxamidate κ-N,N' Pd, κ-S,S' Pd') are reported.

(S)-2-[(2-Hy-droxy-benz-yl)aza-nium-yl]-4-(methyl-sulfan-yl)butano-ate.

The zwitterionic title compound, C(12)H(17)NO(3)S, is a reduced Schiff base derived from (S)-N-(2-hy-droxy-benzyl-idene)methio-nine. An intra-molecular inter-action between the N-H and carboxyl-ate groups forms a roughly planar (r.m.s. deviation = 0.1405 Å) five-membered ring containing the H(N), N, Cα, C(carboxyl-ate) and O atoms in a penta-gonal conformation. In the crystal, a supra-molecular triangle-shaped motif is generated by mol-ecules held together by O-H⋯O and N-H⋯O hydrogen bonds.

3-[2-(1H-1,3-Benzodiazol-2-yl)eth-yl]-1,3-oxazolidin-2-one.

In the title compound, C(12)H(13)N(3)O(2), the dihedral angle between the oxazolone ring and the benzimidazole unit is 45.0 (5)°, exhibiting a staggered conformation at the Cα-Cß bond. In the crystal, a strong N-H⋯N hydrogen bond links the mol-ecules into a C(4) chain along the c axis while a C-H⋯O hydrogen-bonding inter-action generates a C(5) chain along the a axis, i.e. perpendicular to the other chain.

The absolute configuration of palladium(II) and ruthenium(II) pseudochiral centers in either chiral or achiral environments.

The meso-dithioxamide H-((R)-1-(1-phenyl)ethyl)-NSC-CSN-((S)-1-(1-phenyl)ethyl)-H (H(2)-mesoDTO) bonds [(η(6)-p-cymene)chlorido-ruthenium(II)](+) or [(η(3)-allyl)-palladium(II)](+) fragment and provides the C(s) symmetrical complexes [(η(6)-p-cymene)ClRu(H-mesoDTO κ-S,S Ru)] (1) and [(η(3)-allyl)palladium(H-mesoDTO κ-S,S Pd)] (2). These complexes are pseudochiral, and each of them exists as a mixture of two symmetrical meso forms. The improper symmetry of [(η(3)-allyl)palladium(H-mesoDTO κ-S,S Pd)] has been broken in two different ways: (i) by changing the symmetrical allyl moiety with a η(3)-crotyl frame or (ii) by substituting the residual amidic hydrogen in the dithiooxamidate ligand with a M(PR(3))Cl(+) fragment (M = Pd or Pt and PR(3) = triorganophosphine). As a consequence, a chiral plane is added to the pseudochiral palladium center, and two pairs of enantiomers are formed in each case. Furthermore, [(η(6)-p-cymene)chlorido-ruthenium(II)](+) and [(η(3)-allyl)-palladium(II)](+) fragments have been joined by means of the binucleating meso-dithiooxamidate ligand in a κ-S,S Ru κ-N,N Pd coordination mode. The resulting C(s)-symmetrical complex [(η(6)-p-cymene)ClRu(µ-mesoDTO κ-S,S Ru κ-N,N Pd)Pd(η(3)-allyl)] (8) possesses two pseudochiral metal centers, and it is therefore a mixture of four isomeric meso forms. All of these isomers in a chloroform solution interconvert in that both palladium and ruthenium invert their configurations. A mechanism of epimerization for both palladium and ruthenium is proposed. The absolute configurations of pseudochiral palladium in [(η(3)-allyl)(c)-Pd(µ-((R)-1-(1-phenyl)ethyl)-NSC-CSN-((S)-1-(1-phenyl)ethyl) κ-N,N (c)-Pd κ-S,S (A,C)-Pd)(A,C)-Pd(tri(n)propyl-phosphine)Cl] (6) and of pseudochiral palladium and ruthenium in [(η(3)-allyl)(c)-Pd(µ-((R)-1-(1-phenyl)ethyl)-NSC-CSN-((S)-1-(1-phenyl)ethyl) κ-N,N (c)-Pd κ-S,S(s)-Ru)(s)-Ru(η(6)-isopropyltoluene)Cl] (8) are provided. A suitable stereochemical notation is proposed for bimetallic complexes containing pseudochiral centers in either a chiral or an achiral environment.

Dithioether ligands containing a 2,6-disubstituted pyridine linker with two thioether-heterocycle arms.

The structure of 2,6-bis(2-pyridyltsulfanylmethyl)pyridine (pytmp), (I), C(17)H(15)N(3)S(2), presents a twisted conformation, with the three planar moieties almost perpendicular to each other. The structures of two related derivatives, namely 2,6-bis(6-methyl-2-pyridylsulfanylmethyl)pyridine (mpytmp), (II), C(19)H(19)N(3)S(2), and 2,6-bis(4-methyl-2-pyrimidylsulfanylmethyl)pyridine (mprtmp) n-pentane hemisolvate, (III), C(17)H(17)N(5)S(2).0.5C(5)H(12), present extended planar fragments with just one quasi-perpendicular arylsulfanylmethyl side arm, such that the molecules are folded in an L-shaped conformation. All three conformations appear different from those adopted by similar compounds, demonstrating the great flexibility of such species, although such differences in conformational behaviour might drive specific coordination modes.

A functionalized enol lactone containing a protected α-amino acid.

The crystal structure of N-(3,9-dimethyl-4-phenyl-2,5-dioxo-3,4-dihydro-2H,5H-pyrano[3,2-c]chromen-3-yl)-N-methylbenzamide methanol monosolvate, C(28)H(23)NO(5)·CH(3)OH, has been determined at room temperature by X-ray diffraction. Structural parameters are discussed with reference to ab initio calculations.