Co(II) complexes of tetraazamacrocycles appended with amide or hydroxypropyl groups as paraCEST agents.

Co(II) complexes of 1,4,7,10-tetraazacyclododecane (CYCLEN) or 1,4,8,11-tetraazacyclotetradecane (CYCLAM) with 2-hydroxypropyl or carbamoylmethyl (amide) pendants are studied with the goal of developing paramagnetic chemical exchange saturation transfer (paraCEST) agents. Single-crystal X-ray diffraction studies show that two of the coordination cations with hexadentate ligands, [Co(DHP)] and [Co(BABC)], form six-coordinate complexes; whereas two CYCLEN-based complexes with potentially octadentate ligands, [Co(THP)] and [Co(HPAC)], are seven-coordinate with only three of the four pendant groups bound to the metal center. H NMR spectra of these complexes suggest that the six-coordinate complexes are present as a single isomer in aqueous solution.

1,7,7-Trimethyl-3-(naphthalen-2-ylcarbon-yl)bi-cyclo-[2.2.1]heptan-2-one.

The title compound, CHO, crystallizes in its keto form. The mol-ecules are connected weak C-H⋯O inter-actions, forming infinite chains perpendic-ular to the [001] axis.

Naphthalen-1-yl-methanol.

Apart from the OH group, the mol-ecule of the title compound, CHO, is almost planar with all carbon atoms located within 0.03 Å of their mean plane. In the crystal, the mol-ecules are linked by O-H⋯O hydrogen bonds, generating infinite chains running parallel to the [100] direction.

1,2--Iso-propyl-idene-β-d--furan-ose.

In the title compound CHO, the pento-furan-ose five-membered ring has a twisted conformation on two carbon atoms while the five-membered ring of the iso-propyl-idene group has an envelope conformation on an oxygen atom. Hy-droxy groups are involved an infinite network of O-H⋯O hydrogen bonds that leads to the formation of a layer parallel to the (001) plane. Only weak C-H⋯O contacts exist between neighboring layers.

Co Complexes as Liposomal CEST Agents.

Three paramagnetic Co macrocyclic complexes containing 2-hydroxypropyl pendant groups, 1,1',1'',1'''-(1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetrayl)tetrakis- (propan-2-ol) ([Co(L1)] , 1,1'-(4,11-dibenzyl-1,4,8,11-tetraazacyclotetradecane-1,8-diyl)bis(propan-2-ol) ([Co(L2)] ), and 1,1'-(4,11-dibenzyl-1,4,8,11-tetraazacyclotetradecane-1,8-diyl)bis(octadecan-2-ol) ([Co(L3)] ) were synthesized to prepare transition metal liposomal chemical exchange saturation transfer (lipoCEST) agents. In solution, ([Co(L1)] ) forms two isomers as shown by H NMR spectroscopy. X-ray crystallographic studies show one isomer with 1,8-pendants in cis-configuration and a second isomer with 1,4-pendants in trans-configuration.

1,3-Bis(2-oxoprop-yl)thymine.

In the title compound [systematic name: 5-methyl-1,3-bis-(2-oxoprop-yl)pyrimidine-2,4(1,3)-dione], CHNO, the two 2-oxopropyl groups are nearly perpendicular to the planar thymine unit. One methyl group of oxopropyl substituent is disordered. In the crystal, C-H⋯O inter-actions help to connect the mol-ecules into (001) layers.

Isomeric Co(ii) paraCEST agents as pH responsive MRI probes.

A newly discovered isomer of Co(ii) (1,4,8,11-tetrakis(carbamoylmethyl)-1,4,8,11-tetraazacyclotetradecane = CCRM) produces four highly paramagnetically shifted chemical exchange saturation transfer (CEST) peaks. The 1,8-pendants of the complex are bound in a trans-arrangement to produce a Co(ii) complex of increased kinetic inertness. The isomers have a stabilized Co(ii) center (E1/2 of 540 to 550 mV versus SHE).

Characterizing the Image Forming Particles of Modern Ungilded Daguerreotypes Using XRD and SEM.

X-ray diffraction (XRD) and high-resolution scanning electron microscopy (SEM) have been used to characterize the silver mercury amalgam particles resting on the surface that comprise the image of five daguerreotype plates that were not gilded and that were prepared by three different contemporary daguerreotype makers. The regions of interest of the surface that were examined were overexposed, solarized, and highlight (white) areas. The XRD portion of the study shows that the two main silver mercury amalgam particles identified using the International Center for Diffraction Data PF4 + database were the Schachnerite/ζ (zeta) phase amalgam, Ag1.

Crystal structure of ()-1---butyl-diphenyl-silylglycerol: eight chiral mol-ecules in a triclinic cell.

The asymmetric unit of the title compound {systematic name: 3-[(-butyl-diphenyl-sil-yl)-oxy]propane-1,2-diol, CHOSi}, contains eight chiral mol-ecules (' = 8). These mol-ecules are connected a complex system of hydrogen bonds into an infinite assembly along the [100] axis; hydro-phobic -butyl and phenyl groups form an external coating of the assembly. These assemblies are packed by weak inter-molecular inter-actions in a peculiar formation resembling a 'header bond' masonry brick wall.

Crystal structures of binary compounds of meldonium 3-(1,1,1-tri-methyl-hydrazin-1-ium-2-yl)prop-ano-ate with sodium bromide and sodium iodide.

3-(1,1,1-Tri-methyl-hydrazin-1-ium-2-yl)propano-ate (CHNO, , more commonly known under its commercial names or ) co-crystalizes with sodium bromide and sodium iodide forming polymeric hydrates poly[[tetra-μ-aqua-di-aqua-bis-[3-(1,1,1-tri-methyl-hydrazin-1-ium-2-yl)propano-ate]disodium] dibromide tetra-hydrate], [Na(CHNO)(HO)]Br·4HO, and poly[[di-μ-aqua-di-aqua-[μ-3-(1,1,1-tri-methyl-hydrazin-1-ium-2-yl)propano-ate]disodium] diiodide], [Na(CHNO)(HO)]I. The coordination numbers of the sodium ions are 6; the coordination polyhedra can be described as distorted octa-hedra. Metal ions and zwitterions are assembled into infinite layers electrostatic inter-actions and hydrogen-bonded networks.

Low-Spin Fe(III) Macrocyclic Complexes of Imidazole-Appended 1,4,7-Triazacyclononane as Paramagnetic Probes.

Two macrocyclic complexes of 1,4,7-triazacyclononane (TACN), one with N-methyl imidazole pendants, [Fe(Mim)], and one with unsubstituted NH imidazole pendants, [Fe(Tim)], were prepared with a view toward biomedical imaging applications. These low-spin Fe complexes produce moderately paramagnetically shifted and relatively sharp H NMR resonances for paraSHIFT and paraCEST applications. The [Fe(Tim)] complex undergoes pH-dependent changes in NMR spectra in solution that are consistent with the consecutive deprotonation of all three imidazole pendant groups at high pH values.

Crystal structure of strontium and barium acesulafame (6-methyl-4-oxo-4-1,2,3-oxa-thia-zin-3-ide 2,2-dioxide).

Both strontium and barium acesulfames, namely poly[aqua-bis-(μ-6-methyl-2,2-dioxo-1,2λ,3-oxa-thia-zin-4-olato)strontium(II)], [Sr(CHNOS)(HO)] , and the barium(II) analogue, [Ba(CHNOS)(HO)] , crystallize in nearly identical isotypic forms, with barium-oxygen inter-atomic distances being longer due to the larger ionic radius of the barium(II) ion. The coordination number of the metal ion is 9; the coordination polyhedra can be described as distorted capped square anti-prisms [Johnson solid ; Johnson (1966). , 169-200].

Inner-Sphere and Outer-Sphere Water Interactions in Co(II) paraCEST Agents.

High-spin Co(II) complexes are promising for development as paraCEST agents (paraCEST = paramagnetic chemical exchange saturation transfer) for magnetic resonance imaging applications. The first examples of Co(II) paraCEST agents with bound water ligands are presented here. Four Co(II) macrocyclic complexes based on 1,4,7-triazacyclononane and containing either pendent alcohol or pendent amide groups were prepared.

Crystal structure of naltrexone chloride solvates with ethanol, propan-2-ol, and 2-methyl-propan-2-ol.

Naltrexone [systematic name: 17-(cyclo-propyl-meth-yl)-3,14-di-hydroxy-4,5α-epoxymorphinan-6-one] is an opioid receptor competitive antagonist that has been widely used to prevent relapse in opioid- and alcohol-dependent subjects. Its chloride salt forms non-isomorphic solvates with ethanol (CHNO·Cl·CHOH) (I), propan-2-ol (CHNO·Cl·CHOH) (II), and 2-methyl-propan-2-ol (CHNO·Cl·CHOH) (III). The naltrexone cation can be described as a T-shape made out of two ring systems, a tetra-hydro-2-naphtho-[1,8-]furan system and a deca-hydro-isoquinolinium subunit, that are nearly perpendicular to one another.

Crystal structures of bis-[(9,13,14)-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cobaltate and tetra-chlorido-cuprate.

(9,13,14)-3-Meth-oxy-17-methyl-morphinan (dextromethorphan) forms two isostructural salts with () tetra-chlorido-cobaltate, namely bis-[(9,13,14)-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cobaltate, (CHNO)[CoCl], and () tetra-chlorido-cuprate, namely bis-[(9,13,14)-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cuprate, (CHNO)[CuCl]. The distorted tetra-hedral anions are located on twofold rotational axes. The dextromethorphan cation can be described as being composed of two ring systems, a tetra-hydro-naphthalene system + and a deca-hydro-isoquinolinium subunit +, that are nearly perpendicular to one another: the angle between mean planes of the + and + moieties is 78.

Two forms of (naphthalen-1-yl)boronic acid.

Two polymorphs of the title compound, CHBO, were prepared by recystallization from different solvents at room temperature. Both forms demonstrate nearly identical mol-ecular structures with all naphthalene group atoms located in one plane and all boronic acid atoms in another: the dihedral angles between these planes are 39.88 (5) and 40.

Two polymorphs of trans-[3-(3-nitro-phen-yl)oxiran-2-yl](phen-yl)methanone.

The title compound, C15H11NO4, crystallizes in two polymorphic forms, centrosymmetric monoclinic and chiral ortho-rhom-bic. The geometry of the mol-ecules in the two polymorphs is slightly different, possibly due to inter-molecular inter-actions. There are no classical hydrogen bonding in these two structures.

Crystal structure of dimethyl 3,4,5,6-tetra-phenyl-cyclo-hexa-3,5-diene-1,2-di-carboxyl-ate.

In the title compound, C34H28O4, the cyclo-hexa-diene ring has a screw-boat conformation with a torsion angle between the double bonds being on average ca 15° [15.2 (3) and -15.3 (3) in the two independent mol-ecules].

Tuning Up an Electronic Structure of the Subphthalocyanine Derivatives toward Electron-Transfer Process in Noncovalent Complexes with C and C Fullerenes: Experimental and Theoretical Studies.

Noncovalent π-π interactions between chloroboron subphthalocyanine (1), 2,3-subnaphthalocyanine (3), 1,4,8,11,15,18-(hexathiophenyl)subphthalocyanine (4), or 4-tert-butylphenoxyboron subphthalocyanine (2) with C and C fullerenes were studied by UV-vis and steady-state fluorescence spectroscopy, as well as mass (APCI, ESI, and CSI) spectrometry. Mass spectrometry experiments were suggestive of relatively weak interaction energies between compounds 1-4 and fullerenes. The formation of a new weak charge-transfer band in the NIR region was observed in solution only for subphthalocyanine 4 when titrated with C and C fullerenes.

Crystal structure of tris-(3-methyl-1H-pyrazol-1-yl)methane.

The title mol-ecule, C13H16N6, crystallizes from hexane as a mol-ecular crystal with no strong inter-molecular inter-actions (the shortest C-H⋯N contact is longer than 3.38 Å). A relatively short intra-molecular contact (3.

Crystal structure of 1,2-di-benzoyl-ace-naphthyl-ene.

The title mol-ecule, C26H16O2, crystallizes as a mol-ecular crystal with no strong inter-molecular inter-actions (the shortest C-H⋯O contact is longer than 3.4 Å). Two flat ace-naphthyl-ene groups of neigboring 1,2-di-benzoyl-ace-naphthyl-ene mol-ecules are related by a crystallographic center of symmetry and are stacked with the distance between their mean planes of 3.

3-De-oxy-1,2-di-O-isopropyl-idene-5-O-tosyl-d-threo-pentofuran-ose.

In the crystal structure of the title compound, C(15)H(20)O(6)S, the two independent mol-ecules crystalllize in a chiral setting with two different conformations, twisted (4)T(3) and envelope (4)E, for the furan-ose rings. Weak C-H⋯O contacts strengthen the crystal structure.

Tris(5-methylpyrazolyl)methane: synthesis and properties of its iron(II) complex.

The new ligand, tris(5-methylpyrazolyl)methane (1), has been prepared by the reaction of n-butyl lithium with tris(pyrazolyl)methane followed by trimethylation of the tetralithiated species with methyl iodide. The BF(4)(-), ClO(4)(-), and BPh(3)CN(-) salts of the Fe(II) complex of this ligand were also synthesized. The X-ray crystal structure of the BF(4)(-) complex (2) at 100 K had Fe-N bond lengths of 1.

2,6-Anhydro-1,3-di-O-benzyl-d-mannitol.

In the title compound, C(20)H(24)O(5), the six-membered pyran-ose ring adopts a chair conformation. The dihedral angle between the planes of the phenyl groups of the benzyl substituents is 63.1°.

Dimethyl hydrazine-1,2-dicarboxyl-ate-triphenyl-phosphine oxide (1/1).

In the crystal structure of the title compound, C(4)H(8)N(2)O(4)·C(18)H(15)OP, two triphenyl-phosphine oxide mol-ecules and two dimethyl hydrazine-1,2-dicarboxyl-ate mol-ecules are connected via N-H⋯O hydrogen bonds of moderate strength and are related via a twofold rotational axis. Weak C(ar)-H⋯ O contacts strengthen the crystal structure.