Modulating the Amine-CO Interaction Strength: Toward Efficient Carbon Capture.

This study contributes to a comprehensive understanding of the interactions between CO and amines at the molecular level by exploring the rotational spectra of binary complexes between CO and eight different amines through pulsed-jet Fourier transform microwave spectroscopy and quantum chemical calculations. The findings reveal a consistent pattern in which CO is bonded to the amino group, primarily through a C···N tetrel bond, while being supported by C-H···O/C hydrogen bonds. Notably, the binding energies increase from primary through tertiary amines and with increasing chain length of the alkyl groups.

The Effect of Hyperconjugation and Hydrogen Bonding on the Conformers of Methylated Monosaccharides.

The conformational landscapes of four 1-O-methylated monosaccharides-methyl α-glucose, methyl β-glucose, methyl α-galactose, and methyl β-galactose-were characterized using jet-cooled broadband rotational spectroscopy, supported by density functional theory calculations. A newly designed, simple pulsed nozzle assembly was used to introduce the sugar samples into a jet expansion without thermal degradation, eliminating the need for a complex and expensive laser ablation system. Ten conformers were experimentally identified by assigning their rotational spectra, and the intricate methyl internal rotation splittings were analysed.

Rotational Spectroscopy of the Acetone-Water Complex: Large Amplitude Motions.

Acetone (CHCOCH), the simplest ketone, has recently attracted considerable attention for its important role in atmospheric chemistry and in the formation of ices in extraterrestrial sources that contain complex organic molecules. In this study, we employed a combination of experimental rotational spectroscopy and quantum chemistry calculations to investigate the structure and dynamics of the acetone-water complex. Our aim was to understand how non-covalent interactions with water affect the methyl internal rotation dynamics of acetone, and how water-centered large amplitude motions alter the observed physical properties compared to those predicted at the equilibrium position.

Unlocking a new hydrogen-bonding marker: C-O bond shortening in vicinal diols revealed by rotational spectroscopy.

The conformational space of cis-1,2-cyclohexanediol, a model molecule for cyclic vicinal diols, was investigated using rotational spectroscopy and density functional theory calculations. Four low energy conformers within an energy window of 5 kJ mol-1 were identified computationally. A rotational spectrum of jet-cooled cis-1,2-cyclohexanediol was recorded with a chirped pulse Fourier transform microwave spectrometer.

Binary conformers of a flexible, long-chain fluoroalcohol: dispersion controlled selectivity and relative abundances in a jet.

The complex conformational panorama of binary 4,4,4-trifluoro-1-butanol (TFB) aggregates was investigated using chirped-pulse Fourier transform microwave spectroscopy, aided by conformational searches using CREST (Conformer-Rotamer Ensemble Sampling Tool) and quantum chemistry calculations. From nearly 1500 initial dimer geometries, 16 most stable binary candidates were obtained within a relative energy window of ∼4 kJ mol. Rotational spectra of five binary conformers were experimentally observed in supersonic expansion and assigned.

Wetting vs Droplet Aggregation: A Broadband Rotational Spectroscopic Study of 3-Methylcatechol⋅⋅⋅Water Clusters.

Two competing solvation pathways of 3-methylcatechol (MC), an atmospherically relevant aromatic molecule, with up to five water molecules were explored in detail by using a combination of broadband rotational spectroscopy and computational chemistry. Theoretically, two different pathways of solvation emerge: the commonly observed droplet pathway which involves preferential binding among the water molecules while the solute serves as an anchor point for the formation of a water cluster, and an unexpected wetting pathway which involves interactions between the water molecules and the aromatic face of MC, i.e.

Examining the gas-phase homodimers of 3,3,3-trifluoro-1,2-epoxypropane using quantum chemistry and microwave spectroscopy.

Gas phase homodimers of 3,3,3-trifluoro-1,2-epoxypropane (TFO), a molecule which has shown promise as an effective chiral tag for determining the absolute stereochemistry and the enantiomeric composition of chiral analytes, are explored using a variety of quantum chemistry models and rotational spectroscopy. The potential surface governing the interaction of the two molecules is rapidly explored using the artificial bee colony algorithm for homodimer candidates that are subsequently optimized by quantum chemistry methods. Although all model chemistries employed agree that the lowest energy form of the heterochiral homodimer of TFO ( or ) is lower in energy than that of the homochiral dimer ( or ), the energy spacings among the lower energy isomers of each and indeed the absolute energy ordering of the isomers of each are very model dependent.

Conformers of Vanillic Acid and Its Monohydrate: A Rotational Spectroscopic and Theoretical Study.

Organic acids are released during wildfire combustion and can influence aerosol formation and growth. Conformational flexibility is thought to be advantageous in stabilizing the precritical nucleus in the process of aerosol particle formation and allowing for further complexation with other atmospheric constituents. We describe here a study of the conformational flexibility of vanillic acid and its monohydrate using electronic structure calculations and Fourier transform microwave spectroscopy.

Femtosecond Rotational Dynamics of D_{2} Molecules in Superfluid Helium Nanodroplets.

Rotational dynamics of D_{2} molecules inside helium nanodroplets is induced by a moderately intense femtosecond pump pulse and measured as a function of time by recording the yield of HeD^{+} ions, created through strong-field dissociative ionization with a delayed femtosecond probe pulse. The yield oscillates with a period of 185 fs, reflecting field-free rotational wave packet dynamics, and the oscillation persists for more than 500 periods. Within the experimental uncertainty, the rotational constant B_{He} of the in-droplet D_{2} molecule, determined by Fourier analysis, is the same as B_{gas} for an isolated D_{2} molecule.

Rotational Spectroscopy of the 2,2,3,3,3-Pentafluoropropanol⋅⋅⋅Water Complex: Conformations and Large Amplitude Motions.

The 2,2,3,3,3-pentafluoropropanol (PFP) monomer can exist in five conformations defined by the CCCO and CCOH dihedral angles: four mirror-imaged pairs (G+g+/G-g-, G+g-/G-g+, G+t/G-t, Tg+/Tg-) and an achiral Tt form. We examined the conformational landscape of the PFP⋅⋅⋅water complex using chirped pulsed Fourier transform microwave spectroscopy and theoretical calculations. Rotational spectra of two PFP⋅⋅⋅water conformers, PFPG+g+⋅⋅⋅W and PFPTg+⋅⋅⋅W , and seven deuterated isotopologues of each, were assigned.

2,2,3,3,3-Pentafluoro-1-propanol and its dimer: structural diversity, conformational conversion, and tunnelling motion.

Rotational spectra of 2,2,3,3,3-pentafluoro-1-propanol (PFP) were measured using cavity and chirped pulse Fourier transform microwave spectrometers. Of the nine possible PFP configurations which include four mirror-imaged pairs and an achiral conformer, the two most stable monomeric PFP imaged pairs, , PFP++/-- and PFP+/- were observed and assigned, along with the C, O and deuterated isotopologues of PFP++/--. The rotational transitions of PFP+/- exhibit large tunnelling splittings and were analyzed in detail.

Conformational Landscape of the Hydrogen-Bonded 1-Phenyl-2,2,2-Trilfuoroethanol···1,4-Dioxane Complex: Dispersion Interactions and Conformational Conversion.

A rotational spectrum of the hydrogen-bonded complex between 1-phenyl-2,2,2-trilfuoroethanol (PhTFE), a chiral fluoroalcohol, and 1,4-dioxane, a common solvent for organic reactions, was measured using a chirped pulse Fourier transform microwave spectrometer. Initial theoretical conformational searches were carried out using CREST, a recently developed conformational searching tool. Subsequent geometry optimization and harmonic frequency calculations at the B3LYP-D3(BJ)/def2-TZVP level of theory yielded nearly 30 binary conformers of which 13 are within an energy window of ∼5 kJ mol.

High-Normal Preoperative Potassium Level Is Associated with Reduced 30-Day Morbidity and Shorter Hospital Stay after Radical Cystectomy.

Background: Radical cystectomy has high complication rates and, consequently, a high socioeconomic burden. The association between preoperative electrolyte levels and postoperative outcomes after radical cystectomy has not been investigated. Therefore, we aimed to investigate the association between preoperative potassium level and clinical (30-day morbidity) and economical (length of hospital stay) postoperative outcomes of patients undergoing radical cystectomy.

Structural study of 1- and 2-naphthol: new insights into the non-covalent H-H interaction in -1-naphthol.

Previous microwave studies of naphthol monomers were supplemented by measuring spectra of all C mono-substituted isotopologues of the - and -conformers of 1-naphthol and 2-naphthol in their natural abundances. The resulting data were utilized to determine substitution structures and so-called semi-experimental effective structures. Results from electronic structure calculations show that the OH group of -1-naphthol points ≈6° out of plane, which is consistent with the inertial defect data of - and -1-naphthol.

Aggregation of solutes in bosonic versus fermionic quantum fluids.

Quantum fluid droplets made of helium-3 (He) or helium-4 (He) isotopes have long been considered as ideal cryogenic nanolabs, enabling unique ultracold chemistry and spectroscopy applications. The droplets were believed to provide a homogeneous environment in which dopant atoms and molecules could move and react almost as in free space but at temperatures close to absolute zero. Here, we report ultrafast x-ray diffraction experiments on xenon-doped He and He nanodroplets, demonstrating that the unavoidable rotational excitation of isolated droplets leads to highly anisotropic and inhomogeneous interactions between the host matrix and enclosed dopants.

Higher-Energy Hexafluoroisopropanol···Water Isomer and Its Large Amplitude Motions: Rotational Spectra and DFT Calculations.

Rotational spectra of the 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)···water complex were measured using a chirped pulse Fourier-transform microwave spectrometer. The spectral analyses, aided by density functional theory calculations, reveal two HFIP···water isomers: one previously reported, HFIP (HFIP)···water ( 5650-5657), and a new isomer, HFIP (HFIP)···water. To confirm the identity of the new isomer, rotational spectra of seven of its deuterated species were also measured and analyzed.

Orthotopic MAINZ pouch bladder substitution - long-term follow-up.

Introduction: After radical cystectomy, orthotopic neobladder is one surgical strategy for urinary diversion. To assess the usefulness of an operation, long-term data are essential. We examined long-term complications and continence rates of orthotopic ileocecal (MAINZ pouch) bladder substitution.

A rotational spectroscopic and study of - and -(-)-carveol: further insights into conformational dynamics in monoterpenes and monoterpenoids.

Broadband rotational spectra of cis- and trans-(-)-carveol were recorded using a chirped pulse Fourier transform microwave spectrometer in the 2-6 GHz region. To aid in spectroscopic assignments a theoretical conformational search was carried out using a combination of a two dimensional potential energy scan, scanning over the isopropenyl and hydroxyl groups torsional angles, and the Conformer-Rotamer Ensemble Sampling Tool. The theoretical results yielded a total of 23 conformers for the trans- and 19 for the cis-conformer.

Unusual binary aggregates of perylene bisimide revealed by their electronic transitions in helium nanodroplets and DFT calculations.

The S1 ← S0 electronic transition of perylene bisimide (PBI) and its binary aggregates were investigated using a combination of helium nanodroplet isolation spectroscopy and computational methods. First, well-resolved vibronic bands of the PBI monomer obtained under the superfluid helium nanodroplet environment were compared to simulated vibronic spectra with anharmonic corrections of the band positions. Second, about ten sets of weaker vibronic bands were observed, which show similar vibronic patterns as that of the PBI monomer and have their band origins red-shifted by about 8 to 218 cm-1.

Rotational Spectrum and Molecular Structures of the Binary Aggregates of 1,1,1,3,3,3-Hexafluoro-2-propanol with Ne and Ar.

The structures and binding topologies of two binary van der Waals complexes 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)···Ne and ···Ar were investigated. The rotational spectra of these two complexes including several isotopic species containing Ne, Ne, Ar, C, and hydroxyl D were measured using a chirped pulse Fourier transform microwave spectrometer and a cavity-based Fourier transform microwave spectrometer. While HFIP was shown to exist in both the and configurations based on previous reports, the rare gas atom is predicted to attach to HFIP in several different binding topologies, leading to a total of nine possible structural isomers for each complex.

Robotic surgery can be safely performed for patients and healthcare workers during COVID-19 pandemic.

Objectives: To investigate the safety of robotic surgery during COVID-19 pandemic concerning new-acquired COVID-19 infections for patients and healthcare workers.

Patients: We performed a retrospective single-centre cohort study of patients undergoing robotic surgery in initial period of COVID-19 pandemic. Patients and healthcare workers COVID-19 infection status was assessed by structured telephone follow-up and/or repeated nasopharyngeal swabs.

SARS-CoV-2 outbreak in medical employees in a large urologic department: Spread, containment and outcome.

Background: The SARS-CoV-2 pandemic presents an unprecedented challenge to health care systems worldwide. Data on SARS-CoV-2 transmission in a hospital is rare and outbreaks among health care professionals are complex to control.

Material And Methods: Over the course of 6 consecutive weeks we recorded data on an exponential outbreak of SARS-CoV-2 within our department.

Conformational Landscape, Chirality Recognition and Chiral Analyses: Rotational Spectroscopy of Tetrahydro-2-Furoic Acid⋅⋅⋅Propylene Oxide Conformers.

A chiral adduct formed between a chiral carboxylic acid, tetrahydro-2-furoic acid (THFA), and a chiral ester, propylene oxide (PO), was investigated using rotational spectroscopy and DFT calculations. Isolated THFA exists dominantly as three different conformers: I, II, and III in a jet, with I and II taking on the trans-COOH configuration and III having the cis-COOH configuration. We utilized CREST, a conformational ensemble space exploration tool, to identify the possible conformations of the binary adduct, THFA⋅⋅⋅PO.

The timing of initial imaging in testicular cancer: impact on radiological findings and clinical decision making.

Background: In testicular cancer determination of clinical stage and recommendation of therapeutic strategy after inguinal orchiectomy are based on primary imaging by CT-scan of the chest and CT- or MRI-abdomen. It has not been investigated so far whether the imaging should be performed before or after primary testicular surgery. Staging before surgery means exposing all patients to CT radiation irrespective of ensured histologic malignancy while postoperative staging could pose a risk in biased clinical decision making by increased presence of unspecific lymph node enlargement caused by postsurgical effects.