Crystal structure of cis-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N)bis-(thio-cyanato-κN)chromium(III) bromide from synchrotron X-ray diffraction data

The crystal structure of the title complex, cis-[Cr(NCS)2(cyclam)]Br (cyclam = 1,4,8,11-tetra-aza-cyclo-tetra-decane, C10H24N4), has been determined from synchrotron X-ray data. The asymmetric unit contains one [Cr(NCS)2(cyclam)]+ cation and one bromide anion. The CrIII ion of the complex cation is coordinated by the four N atoms of the cyclam ligand and by two N-coordinating NCS groups in a cis arrangement, displaying a distorted octa-hedral coordination sphere. The Cr-N(cyclam) bond lengths are in the range 2.075 (3) to 2.081 (3) Å while the average Cr-N(NCS) bond length is 1.996 (16) Å. The macrocyclic cyclam moiety adopts the most stable cis-V conformation. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the cyclam N-H groups as donor groups, and the bromide anion and the S atom of one of the NCS ligands as acceptor groups.

Crystal structure of 3,14-diethyl-2,6,13,17-tetra-azoniatri-cyclo-[16.4.0.07,12]docosane tetra-chloride tetra-hydrate from synchrotron X-ray data

The crystal structure of the hydrated title salt, C22H48N4 4+·4Cl-·4H2O (C22H48N4 = H4 L = 3,14-diethyl-2,6,13,17-tetra-azoniatri-cyclo-[16.4.0.07,12]doco-sa-ne), has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit comprises one half of the macrocyclic cation (completed by crystallographic inversion symmetry), two chloride anions and two water mol-ecules. The macrocyclic ring of the tetra-cation adopts an exodentate (3,4,3,4)-D conformation. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the macrocycle N-H groups and water O-H groups as donors, and the O atoms of the water mol-ecules and chloride anions as acceptors, giving rise to a three-dimensional network.

Early stage of the single-crystal growth and tipping point of the cationic site preference in Gd-doped Zintl phase thermoelectric materials

Three novel Zintl phases in the Ca11−xGdxSb10−y system were synthesized, and the early stage of the single-crystal growth process and the “tipping point” of the cationic site preference for the size-factor criterion were thoroughly investigated.

Symmetrical and unsymmetrical thiazole-based ESIPT derivatives: the highly selective fluorescence sensing of Cu2+ and structure-controlled reversible mechanofluorochromism

Excited state intramolecular proton transfer (ESIPT) process-based organic fluorophores provide an opportunity to develop large Stokes-shifted multifunctional fluorescence systems for light emitting, chemosensing and bioimaging applications.

Molecular conformational twist-controlled wide fluorescence tuning and white light emission in a single fluorophore via halochromism

Conformational differences-controlled fluorescence response of carbazole and triphenylamine appended cyano-pyridine donor–acceptor derivatives towards organic acids (TFA/PTSA).

Robotic prostatectomy after abandoned open radical prostatectomy—Technical aspects and outcomes

Objective

To describe the technical aspects and outcomes of robotic‐assisted radical prostatectomy (RARP) following abandoned open radical prostatectomy (ORP).

Patients and Methods

A retrospective review was performed of patients who underwent RARP following abandonment of ORP between 2016 and 2020. RARP was undertaken by two highly experienced robotic surgeons. Analysis of patient and operative characteristics, outcomes, and reasons for abandonment of ORP were described.

Results

Six patients were included for analysis with a median age of 63.5 years [50.3‐67.5]. The median body mass index (BMI) was 34.7 [27.8‐36.2]. All patients had intermediate‐risk prostate cancer. Small prostate and deep pelvis were given as reasons for abandoning ORP in five cases (83.3%), with four of these also attributing increased BMI as a factor. Extensive mesh from previous bilateral inguinal hernia repair was cited as the reason for abandonment in the remaining patient. One patient had commenced androgen deprivation therapy following abandoned ORP. Extensive retropubic adhesions were noted at the time of RARP in five of six patients, with intraoperative complication of small bladder lacerations encountered in the patient with prior mesh hernia repair. The median time from abandoned ORP to RARP was 128 days [40‐216]. Median operating time was 160 minutes [139‐190] and estimated blood loss was 225 mL [138‐375]. Negative margins were obtained in four of six cases, with further salvage treatment being required in one case at a median follow‐up duration of 10.5 months [6.5‐25.3].

Conclusion

Abandonment of ORP is an uncommonly reported event, however, in this small case series, we demonstrate that, in the hands of experienced surgeons, RARP is a safe and technically feasible alternative in such cases. Increased BMI, small prostate size and pelvic anatomical constraints appear to be common catalysts for abandonment of open surgery in this cohort. Identifying these high‐risk patients early and considering referral to robotic centers may be preferred.

Rational design of a robust aluminum metal-organic framework for multi-purpose water-sorption-driven heat allocations

Adsorption-driven heat transfer technology using water as working fluid is a promising eco-friendly strategy to address the exponential increase of global energy demands for cooling and heating purposes. Here we present the water sorption properties of a porous aluminum carboxylate metal-organic framework, [Al(OH)(C₆H₃NO₄)]·nH₂O, KMF-1, discovered by a joint computational predictive and experimental approaches, which exhibits step-like sorption isotherms, record volumetric working capacity (0.36 mL mL⁻¹) and specific energy capacity (263 kWh m⁻³) under cooling working conditions, very high coefficient of performances of 0.75 (cooling) and 1.74 (heating) together with low driving temperature below 70 °C which allows the exploitation of solar heat, high cycling stability and remarkable heat storage capacity (348 kWh m⁻³). This level of performances makes this porous material as a unique and ideal multi-purpose water adsorbent to tackle the challenges of thermal energy storage and its further efficient exploitation for both cooling and heating applications.

Adsorption-based heat transfer devices are attractive for clean energy resources, but those using water as the working fluid require suitable water adsorbents. Here the authors use computation and experiment to develop an aluminum-based metal-organic framework adsorbent for adsorption-driven heat transfer devices.

Two Steps to Improve the Thermoelectric Performance of the Ca5-xYbxAl2-yInySb6 System

A series of quaternary and quinary Zintl phase thermoelectric (TE) compounds, Ca_5-xYb_xAl_2-yIn_ySb₆ (3.07(1) ≤ x ≤ 4.88(2); 0.16(2) ≤ y ≤ 2.00), containing Al/In mixed sites as well as Ca/Yb mixed sites has been successfully synthesized by a direct arc-melting method, and the X-ray diffraction analyses indicated that the products initially adopted an orthorhombic Ba₅Al₂Bi₆-type structure (space group Pbam, Z = 2). However, after a postannealing process at 973 K for 1 month, the particular Yb rich compounds underwent a transformation of the original structure type to a Ca₅Ga₂Sb₆-type phase regardless of the In substitution for Al. The noticeable site preference of cationic Ca and Yb in the three available cationic sites could be understood on the basis of a size match between the central cation and the volume of the anionic polyhedra. The observed phase transition was nicely explained by DFT calculations, proving that the Ca₅Ga₂Sb₆-type phase was energetically more favorable than the Ba₅Al₂Sb₆-type phase for the particular Yb-rich compound. Moreover, this energy difference between the two title phases was originally the result of both the site energy in the Ca site and the bond energies in the [(Al/In)₂Sb₈] anionic building blocks. A series of thermoelectric property data indicated that a two-step process involving a partial/full In substitution for Al and a phase transition from the Ba₅Al₂Sb₆-type to the Ca₅Ga₂Sb₆-type phase successfully enhanced the electrical conductivities and the Seebeck coefficients of the title compounds. This kind of combined effect eventually resulted in a ZT improvement for the quinary compound Ca_1.14(2)Yb_3.86Al_1.68(1)In_0.32Sb₆ by approximately 4 times in comparison to its quaternary predecessor Ca_1.55(1)Yb_3.45Al₂Sb₆.

Microscopic and Mesoscopic Dual Postsynthetic Modifications of Metal-Organic Frameworks

We report the dual postsynthetic modification (PSM) of a metal-organic framework (MOF) involving the microscopic conversion of C-H bonds into C-C bonds and the mesoscopic introduction of hierarchical porosity. MOF crystals underwent single-crystal-to-single-crystal transformations during the electrophilic aromatic substitution of Co₂ (m-DOBDC) (m-DOBDC^4- =4,6-dioxo-1,3-benzenedicarboxylate) with alkyl halides and formaldehyde. The steric hindrance caused by the proximity of the introduced functional groups to the coordination bonds reduced bond stability and facilitated the transformation into hierarchically porous mesostructures by etching with in situ generated protons (hydroniums) and halides. The numerous defect sites in the mesostructural MOFs are potential water-sorption sites. However, since the introduced functional groups are close to the main adsorption sites, even methyl groups are able to considerably decrease water adsorption, whereas hydroxy groups increase adsorption at low vapor pressures.

Response to Comment on "Dry reforming of methane by stable Ni-Mo nanocatalysts on single-crystalline MgO"

Hu and Ruckenstein state that our findings were overclaimed and not new, despite our presentation of evidence for the Nanocatalysts on Single Crystal Edges (NOSCE) mechanism. Their arguments do not take into account fundamental differences between our Ni-Mo/MgO catalyst and their NiO/MgO preparations.

Chiral Pd6L8 Nanocube Pairs: Recognition of Chiral Amino Acids via Electrochemistry

The self-assembly of PdX₂ (X^- = ClO₄^- and PF₆^-) with C₃-symmetric l- and d-L [L = (2S,2'S,2″S)- and (2R,2'R,2″R)-[benzenetricarbonyltris(azanediyl)]tris(3-phenylpropane-2,1-diyl)triisonicotinate] produces the chiral nanocube pair [Pd₆(l-L)₈](X)₁₂ and [Pd₆(d-L)₈](X)₁₂ (X^- = ClO₄^- and PF₆^-, respectively) with an inner cavity of 12.3 × 12.3 × 12.3 ų. These chiral nanocubes are effective for the enantiorecognition of various chiral amino acids via the square-wave-voltammetry technique. In the present study, the site of enantiorecognition was confirmed by density functional theory calculated interactions between each nanocube and the chiral amino acids, and the calculated interactions were coincident with the shifts of the electrochemical oxidation potentials.

Crystal structure of trans-di-chlorido-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N)chromium(III) bis-(form-amide-κO)(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N)chromium(III) bis-[tetra-chlorido-zincate(II)]

The structure of the title compound, [CrCl2(C10H24N4)][Cr(HCONH2)2(C10H24N4)][ZnCl4]2 (C10H24N4 = 1,4,8,11-tetra-aza-cyclo-tetra-decane, cyclam; HCONH2 = formamide, fa), has been determined from synchrotron X-ray data. The asymmetric unit contains two independent halves of the [CrCl2(cyclam)]+ and [Cr(fa)(cyclam)]3+ cations, and one tetra-chlorido-zincate anion. In each complex cation, the CrIII ion is coordinated by the four N atoms of the cyclam ligand in the equatorial plane and two Cl ligands or two O-bonded formamide mol-ecules in a trans axial arrangement, displaying a distorted octa-hedral geometry with crystallographic inversion symmetry. The Cr-N(cyclam) bond lengths are in the range 2.061 (2) to 2.074 (2) Å, while the Cr-Cl and Cr-O(fa) bond distances are 2.3194 (7) and 1.9953 (19) Å, respectively. The macrocyclic cyclam moieties adopt the centrosymmetric trans-III conformation with six- and five-membered chelate rings in chair and gauche conformations. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the NH or CH groups of cyclam and the NH2 group of coordinated formamide as donors, and Cl atoms of the ZnCl4 2- anion as acceptors.

Dry reforming of methane by stable Ni-Mo nanocatalysts on single-crystalline MgO

Large-scale carbon fixation requires high-volume chemicals production from carbon dioxide. Dry reforming of methane could provide an economically feasible route if coke- and sintering-resistant catalysts were developed. Here, we report a molybdenum-doped nickel nanocatalyst that is stabilized at the edges of a single-crystalline magnesium oxide (MgO) support and show quantitative production of synthesis gas from dry reforming of methane. The catalyst runs more than 850 hours of continuous operation under 60 liters per unit mass of catalyst per hour reactive gas flow with no detectable coking. Synchrotron studies also show no sintering and reveal that during activation, 2.9 nanometers as synthesized crystallites move to combine into stable 17-nanometer grains at the edges of MgO crystals above the Tammann temperature. Our findings enable an industrially and economically viable path for carbon reclamation, and the "Nanocatalysts On Single Crystal Edges" technique could lead to stable catalyst designs for many challenging reactions.

Crystal structure of 1,4,8,11-tetra-methyl-1,4,8,11-tetra-azonia-cyclo-tetra-decane bis-[chlorido-chromate(VI)] dichloride from synchrotron X-ray data

The crystal structure of title compound, (C14H36N4)[CrO3Cl]2Cl2, has been determined by synchrotron radiation X-ray crystallography at 220 K. The macrocyclic cation lies across a crystallographic inversion center and hence the asymmetric unit contains one half of the organic cation, one chloro-chromate anion and one chloride anion. Both the Cl- anion and chloro-chromate Cl atom are involved in hydrogen bonding. In the crystal, hydrogen bonds involving the 1,4,8,11-tetra-methyl-1,4,8,11-tetra-azonia-cyclo-tetra-decane (TMC) N-H groups and C-H groups as donor groups and three O atoms of the chloro-chromate and the chloride anion as acceptor groups link the components, giving rise to a three-dimensional network.

Solvent-triggered single-crystal-to-single-crystal transformation from a monomeric to polymeric copper(II) complex based on an aza macrocyclic ligand

Reversible solvent-triggered single-crystal-to-single-crystal (SCSC) transformations are observed between two copper(II) azamacrocyclic complexes: [Cu(C₁₆H₃₈N₆)(H₂O)₂](C₁₂H₆O₄) (1) and [Cu(C₁₆H₃₈N₆)(C₁₂H₆O₄)] (2). Complex (1) was prepared via self-assembly of a copper(II) azamacrocyclic complex containing butyl pendant groups, [Cu(C₁₆H₃₈N₆)(ClO₄)₂], with 2,7-naphthalenedicarboxylic acid. When monomeric compound (1) was immersed in CH₃OH, coordination polymer (2) was obtained, indicating a solvent-triggered SCSC transformation. Furthermore, when (2) was immersed in water, an reverse SCSC transformation from (2) to (1) occurred. Complex (1) presents a 3D supramolecular structure formed via intermolecular hydrogen-bonding interactions, whereas complex (2) features a 1D zigzag coordination polymer. The reversible SCSC transformation of (1) and (2) was characterized using single-crystal X-ray diffraction and in situ powder X-ray diffraction techniques. Despite its poor porosity, complex (2) displayed interesting CO₂ adsorption behaviour under CO₂ gas.

Crystal structure of 1,4,8,11-tetra-methyl-1,4,8,11-tetra-azonia-cyclo-tetra-decane bis-(perchlorate) dichloride from synchrotron X-ray data

In the title salt, [C₁₄H₃₆N₄]⁴⁺·2ClO₄⁻·2Cl⁻, the macrocyclic cations lie about an inversion center. In the crystal, N–H⋯Cl, C–H⋯Cl and C–H⋯O hydrogen bonds connect the cations and anions, forming a three-dimensional network.

The crystal structure of title salt, C₁₄H₃₆N₄⁴⁺·2ClO₄⁻·2Cl⁻, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit contains one half-cation (completed by crystallographic inversion symmetry), one perchlorate anion and one chloride anion. A distortion of the perchlorate anion is due to its involvement in hydrogen-bonding inter­actions with the cations. The crystal structure is consolidated by inter­molecular hydrogen bonds involving the 1,4,8,11-tetra­methyl-1,4,8,11-tetra­azonia­cyclo­tetra­decane N—H and C—H groups as donor groups, and the O atoms of the perchlorate and chloride anion as acceptor groups, giving rise to a three-dimensional network.