ß-Cyclodextrin capped ZnS nanoparticles for CER-assisted colorimetric and spectrophotometric detection of Pb2⁺, Cu2⁺, and Hg2⁺ in an aqueous solution.

Herein, simple, low-cost, and room-temperature synthesis of beta-cyclodextrin (ß-CD) stabilized zinc sulfide nanoparticle (ZnS NP) through the chemical precipitation method has been reported for cation exchange reaction (CER) based colorimetric sensing of Pb2+, Cu2+, and Hg2+. Formation of ß-CD stabilized ZnS NPs (ZnS@ß-CD) was verified by physicochemical characterization techniques such as XRD, XPS, FE-SEM, and TEM. ZnS@ß-CD NPs showed color change selectively for the metal ions Pb2⁺, Cu2⁺, and Hg2⁺ among the various metal ions including Sn2⁺, Cr³âº, Mn2⁺, Fe³âº, Co2⁺, Ni2⁺, and Cd2⁺. The solubility product of reactants and the transformed products are the reason for selective CER of ZnS@ß-CD NPs towards Pb2⁺, Cu2⁺, and Hg2⁺ ions. ZnS@ß-CD NPs dispersion revealed rapid color change from white to orange, black, and bright yellow on the addition of higher concentrations of Pb2⁺, Cu2⁺, and Hg2⁺ respectively. This color change is due to the formation of complete CER-transformed nanostructures such as PbS, CuS, and HgS in higher concentrations (10⁻1- 10⁻³ M) of corresponding metal ions. The partial CER altered products Zn1-x,PbxS, Zn1-xCuxS and Zn1-xHgxS were detected due to the appearance of pale color in the lower metal ions concentrations of 10⁻4 - 10⁻6 M. This CER assisted transformation was also monitored through spectrophotometric methods. Moreover, infrared spectroscopic analysis was used to testify the structure of CER transformed product. The synthesized ZnS@ß-CD NPs act as an efficient CER-based sensor for distinguishing and determining Pb2⁺, Cu2⁺, and Hg2⁺ at different level concentrations in the aqueous solution.

Comparison of Non-Contrast Cardiovascular Magnetic Resonance Imaging to Computed Tomography Angiography for Aortic Annular Sizing Before Transcatheter Aortic Valve Replacement.

BACKGROUND: Accurate measurement of aortic annulus is crucial before transcatheter aortic valve replacement (TAVR). Computed tomography (CT) angiography is the most commonly utilized method, but requires contrast administration. Cardiovascular magnetic resonance (CMR) imaging is a promising alternative modality to provide aortic annulus measurements. Few studies have compared the clinical feasibility and accuracy of non-contrast CMR to contrast-enhanced computed tomography (CT) angiography in order to provide a non-contrast alternative to CT annular sizing. METHODS: Twenty-one consecutive patients (mean age, 85.7 ± 5.2 years) with severe aortic stenosis (mean aortic valve area, 0.6 ± 0.1 cm²) underwent pre-TAVR CT angiography and a non-contrast CMR at 1.5 T. CT measurements were performed during systole as the clinical non-invasive standard. CMR measurements were performed during systole and diastole and included three-dimensional (3D) and two-dimensional (2D) methods. Interobserver differences were assessed using intraclass correlation. We recorded scan time in each patient. RESULTS: The mean systolic annular area was not significantly different between CT and 3D-CMR (480.0 ± 77.9 mm² vs 479.4 ± 66.2 mm²; P=.98) in systole. There was no clinically relevant systematic difference between area measurements [mean difference, 0.6 mm²; limits of agreement -38.2 mm²; 39.3 mm²] using Bland-Altman analyses. Interobserver correlation was excellent. The diagnostic systolic 3D-CMR annular sizing scan was achieved in 4.4 ± 2.7 min. CONCLUSION: Non-contrast CMR protocol for the measurement of aortic annulus area is feasible and accurate. 3D-CMR could provide an alternative for annular sizing pre-TAVR assessment in patients who cannot undergo contrast-enhanced CT studies.

Crystal structure of (E)-2-(4-meth-oxy-styr-yl)-3-methyl-1-phenyl-sulfonyl-1H-indole.

In the title compound, C24H21NO3S, the dihedral angles between the indole ring system (r.m.s. deviation = 0.030 Å) and the sulfur and ethyl-ene-bonded benzene rings are 80.2 (2) and 49.29 (15)°, respectively. The dihedral angle between the pendant benzene rings is 37.7 (2)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and weak C-H⋯π and π-π [centroid-to-centroid distances = 3.549 (2) and 3.743 (3) Å] inter-actions, forming a three-dimensional network.

Crystal structure of ethyl 2-phenyl-9-phenyl-sulfonyl-9H-carbazole-3-carboxyl-ate.

In the title compound, C27H21NO4S, the dihedral angles between the carbazole ring system (r.m.s. deviation = 0.015 Å) and the sulfur-bonded and directly linked benzene rings are 79.98 (11) and 53.51 (18)°, respectively. The benzene rings subtend a dihedral angle of 48.4 (2)°. The ethyl side chain of the ester group has an extended conformation [C-O-C-C = -172.3 (3)°]. In the crystal, inversion dimers linked by pairs of weak C-H⋯O hydrogen bonds generate R 2 (2)(22) loops. The dimers are linked by weak C-H⋯π and π-π [centroid-to-centroid distances ranging from 3.5042 (14) to 3.888 (2) Å] inter-actions, thereby forming a three-dimensional supra-molecular network.

Crystal structure of N-{[3-bromo-1-(phenyl-sulfon-yl)-1H-indol-2-yl]meth-yl}benzene-sulfonamide.

In the title compound, C21H17BrN2O4S2, the indole ring system subtends dihedral angles of 85.96 (13) and 9.62 (16)° with the planes of the N- and C-bonded benzene rings, respectively. The dihedral angles between the benzene rings is 88.05 (17)°. The mol-ecular conformation is stabilized by intra-molecular N-H⋯O and C-H⋯O hydrogen bonds and an aromatic π-π stacking [centroid-to-centroid distance = 3.503 (2) Å] inter-action. In the crystal, short Br⋯O [2.9888 (18) Å] contacts link the mol-ecules into [010] chains. The chains are cross-linked by weak C-H⋯π inter-actions, forming a three-dimensional network.

Crystal structure of 3-(2-nitro-phen-yl)-1-(1-phenyl-sulfonyl-1H-indol-3-yl)propan-1-one.

In the title compound, C23H18N2O5S, the phenyl and benzene rings subtend dihedral angles of 78.18 (10) and 30.18 (9)°, respectively, with the indole ring system (r.m.s. deviation = 0.022 Å). The crystal structure features weak C-H⋯O and C-H⋯π inter-actions, which link the mol-ecules into a three-dimensional network.

Crystal structure of (2-methyl-1-phenyl-sulfon-yl-1H-indol-3-yl)(phen-yl)methanone.

In the title compound, C22H17NO3S, the sulfonyl-bound phenyl ring is almost orthogonal to the indole ring system, making a dihedral angle of 84.89 (7)°. The carbonyl-bound phenyl ring forms a dihedral angle of 57.32 (5)° with the indole ring system. The two phenyl rings are inclined at 52.68 (7)°. The S atom has a distorted tetra-hedral configuration. In the crystal, weak C-H⋯O inter-actions link the mol-ecules, forming a helical chain along the b-axis direction.

Crystal structure of (2-bromo-methyl-1-phenyl-sulfonyl-1H-indol-3-yl)(phen-yl)methanone.

In the title compound, C22H16BrNO3S, the phenyl rings make dihedral angles of 84.81 (16) and 61.67 (17)° with the indole ring system (r.m.s. deviation = 0.012 Å), while the phenyl rings are inclined to one another by 69.5 (2)°. The mol-ecular structure is stabilized by weak intra-molecular C-H⋯O hydrogen bonds. The sulfonyl S atom has a distorted tetra-hedral configuration. In the crystal, there are no significant inter-molecular inter-actions present.

Crystal structure of (E)-diethyl 2-[(1-phenyl-sulfonyl-1H-indol-3-yl)methyl-idene]succinate.

In the title compound, C23H23NO6S, the phenyl ring is perpendicular [dihedral angle = 89.34 (9)°] to the indole ring system. In the mol-ecule, the eth-oxy groups are each disordered over two sets of sites with occupancy ratios of 0.671 (6):0.329 (6) and 0.75 (3):0.25 (3). The mol-ecular conformation is consolidated by a weak C-H⋯O interaction, which generates an S(6) graph-set motif. The packing of the mol-ecules in the crystal structure features weak C-H⋯π inter-actions.

Crystal structure of 2-[2-phenyl-1-(phenyl-sulfon-yl)eth-yl]-1-phenyl-sulfonyl-1H-indole.

In the title compound, C28H23NO4S2, the indole ring system (r.m.s. deviation = 0.007 Å) subtends dihedral angles of 78.69 (13) and 38.97 (13)° with the planes of the N- and C-bonded sulfonyl-benzene rings, respectively, and these two benzene rings are inclined to each other at an angle of 65.45 (16)°. The methyl-ene-linked phenyl ring is twisted at an angle of 81.80 (13)° from the indole ring. The mol-ecular structure features two short intra-molecular C-H⋯O contacts, which both generate S(6) rings. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and C-H⋯π inter-actions, generating a three-dimensional network.

Crystal structure of 2-(2,4-di-chloro-phen-yl)-4-hydroxy-9-phenyl-sulfonyl-9H-carbazole-3-carbaldehyde.

In the title compound, C25H15Cl2NO4S, the di-chloro-phenyl ring is twisted by 68.69 (11)° from the mean plane of the carbazole ring system [r.m.s. deviation = 0.084 (2)°]. The hy-droxy group is involved in an intra-molecular O-H⋯O hydrogen bond, which generates an S(6) graph-set motif. In the crystal, pairs of C-H⋯Cl hydrogen bonds link mol-ecules into inversion dimers with an R (2) 2(26) motif. Weak C-H⋯O inter-actions further link these dimers into ribbons propagating in [100].

(E)-1-[2-(4-Chloro-2-nitro-styr-yl)-1-phenyl-sulfonyl-1H-indol-3-yl]propan-1-one.

In the title compound, C25H19ClN2O5S, the phenyl ring forms dihedral angles of 79.62 (12) and 80.02 (13)° with the indole ring system and the benzene ring, respectively. The nitro group is twisted at an angle of 22.39 (11)° with respect to the attached benzene ring. In the crystal, mol-ecules assemble into double layers in the ab plane via C-H⋯O inter-actions.

(E)-1-[2-(4-Fluoro-2-nitro-styr-yl)-1-phenyl-sulfonyl-1H-indol-3-yl]propan-1-one.

In the title compound, C25H19FN2O5S, the substituted phenyl ring makes a dihedral angle of 12.26 (9)° with the indole ring system. The nitro group is twisted at an angle of 26.92 (8)° out of the plane of the ring to which it is attached. The mol-ecular structure is stabilized by weak C-H⋯O hydrogen bonds. In the crystal, weak C-H⋯O, C-H⋯F and π-π [centroid-centroid distance = 3.6645 (11) Å] inter-actions link the mol-ecules, forming a three-dimensional network.

(Z)-3-(1-Chloro-prop-1-en-yl)-2-methyl-1-phenyl-sulfonyl-1H-indole.

In the title compound, C18H16ClNO2S, the indole ring system forms a dihedral angle of 75.07 (8)° with the phenyl ring. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen bond. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming a chain along [10-1]. C-H⋯π inter-actions are also observed, leading to a three-dimensional network.

1-(2-Bromo-meth-yl-1-phenyl-sulfonyl-1H-indol-3-yl)propan-1-one.

In the title compound, C18H16BrNO3S, the dihedral angle between the phenyl ring and the indole ring system is 89.91 (11)°. The mol-ecular structure features weak C-H⋯O and C-H⋯Br hydrogen bonds. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming chains along the a-axis direction. The chains are further linked by C-H⋯π inter-actions, forming a layer parallel to the ab plane.