267 research outputs found
cis-(Nitrato-κ2 O,O′)(2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclotetradecane-κ4 N,N′,N′′,N′′′)cadmium nitrate hemihydrate
The CdII atom in the title complex, [Cd(NO3)(C18H40N4)]NO3·0.5H2O, is coordinated within a cis-N4O2 donor set provided by the tetradentate macrocyclic ligand and two O atoms of a nitrate anion; the coordination geometry is distorted octahedral. The lattice water molecule is located on a twofold rotation axis. N—H⋯O hydrogen bonds and weak C—H⋯O interactions link the complex cations into a supramolecular layer in the bc plane. Layers are connected by O—H⋯O hydrogen bonds between the lattice water molecule and the non-coordinating nitrate anion, as well as by weak C—H⋯O contacts
5,7,7,12,14,14-Hexamethyl-4,11-diaza-1,8-diazoniacyclotetradecane bis(perchlorate) monohydrate
In the title hydrated salt, C16H38N4
2+·2ClO4
−·H2O, the dication is protonated at the diagonally opposite N atoms proximate to the –C(CH3)2– groups. Within the cavity, there are two ammonium–amine N—H⋯N hydrogen bonds. Supramolecular layers are formed in the crystal packing whereby the water molecule links two perchlorate anions, and the resultant aggregates are connected to the dications via N—H⋯O hydrogen bonds. Layers, with an undulating topology, stack along the a axis being connected by C—H⋯O interactions
(Acetato-κO)(2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclotetradecane-κ4 N,N′,N′′,N′′′)zinc perchlorate
The ZnII atom in the cation of the title salt, [Zn(C2H3O2)(C18H40N4)]ClO4, is five-coordinated by the four N atoms of the macrocycle and the O atom of the monodentate acetate ligand. The N4O donor set is based on a trigonal bipyramid with two N atoms occupying axial positions [N—Zn—N = 170.89 (16)°]. The perchlorate anions are associated with the cations via N—H⋯O hydrogen bonds; intramolecular N—H⋯O(acetate) interactions are also observed. The neutral aggregates are connected into an helical chain along the b axis via N—H⋯O(acetate) hydrogen bonds. The perchlorate anion was found to be disordered about a pseudo-threefold axis: the major component of the disorder had a site occupancy factor of 0.692 (11)
[(4E,11E)-5,7,12,14-Tetrabenzyl-7,14-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene]copper(II) bis(perchlorate)
The complete cation in the title compound, [Cu(C40H48N4)](ClO4)2, is generated by the operation of a crystallographic centre of inversion. The CuII ion exists in a tetragonally distorted trans-N4O2 coordination geometry defined by the four N atoms of the macrocyclic ligand and two weakly bound perchlorate-O atoms from two anions. The N—H atoms form intramolecular N—H⋯O(perchlorate) hydrogen bonds. Disorder was resolved in the –CH2–NH– portion of the macrocycle with the major component having a site-occupancy factor of 0.570 (6)
Dichlorido[(4E,11E)-5,7,12,14-tetrabenzyl-7,14-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene]cobalt(III) perchlorate
The CoIII atom in the title complex, [CoCl2(C40H48N4)]ClO4, is octahedrally coordinated within a trans-Cl2N4 donor set provided by the tetradentate macrocylic ligand and two chloride ions. The N—H atoms, which are orientated to one side of the N4 plane, form hydrogen bonds with chloride ions and perchlorate-O atoms. These along with C—H⋯O interactions consolidate the three-dimensional crystal structure. One of the benzene rings was disordered. This was resolved over two positions with the major component of the disorder having a site-occupancy factor of 0.672 (4)
3,10-C-meso-3,5,7,7,10,12,14,14-Octamethyl-4,11-diaza-1,8-diazoniacyclotetradecane bis(perchlorate)
The structure determination of the title salt, C18H42N4
2+·2ClO4
−, reveals that protonation has occurred at diagonally opposite amine N atoms. Intramolecular N—H⋯N hydrogen bonds stabilize the conformation of the dication. In the crystal, the dications are bridged by perchlorate ions via N—H⋯O hydrogen bonds into supramolecular chains propagating along the c axis and weak C—H⋯O interactions cross-link the chains
Synthesis, Characterisation and Antifungal Activities of Some New Copper(II) Complexes of Isomeric 3,5,7,7,10,12,14,14-Octamethyl-1,4,8,11-Tetraazacyclotetradecanes
Three isomeric Me8[14]anes, LA, LB and LC, undergo complexation with copper(II) salts to form a series of [CuLXn(H2O)x]Xy.(H2O)z complexes where L = LA, LB and LC; X = Cl, Br, NO3; n, x, y and z may have values of 0, 1 or 2. The complexes have been characterised on the basis of analytical, spectroscopic, magnetic and conductance data. Further, the X-ray crystal structure of one complex, [CuLB(OH2)2](NO3)2, has been determined. The antifungal activity of all three isomeric ligands and their complexes has been investigated against a range of phytopathogenic fungi
Role of Autonomic Reflex Arcs in Cardiovascular Responses to Air Pollution Exposure
The body responds to environmental stressors by triggering autonomic reflexes in the pulmonary receptors, baroreceptors, and chemoreceptors to maintain homeostasis. Numerous studies have shown that exposure to various gases and airborne particles can alter the functional outcome of these reflexes, particularly with respect to the cardiovascular system. Modulation of autonomic neural input to the heart and vasculature following direct activation of sensory nerves in the respiratory system, elicitation of oxidative stress and inflammation, or through other mechanisms is one of the primary ways that exposure to air pollution affects normal cardiovascular function. Any homeostatic process that utilizes the autonomic nervous system to regulate organ function might be affected. Thus, air pollution and other inhaled environmental irritants have the potential to alter both local airway function and baro-and chemoreflex responses, which modulate autonomic control of blood pressure and detect concentrations of key gases in the body. While each of these reflex pathways causes distinct responses, the systems are heavily integrated and communicate through overlapping regions of the brainstem to cause global effects. This short review summarizes the function of major pulmonary sensory receptors, baroreceptors, and carotid body chemoreceptors and discusses the impacts of air pollution exposure on these systems
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