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1.
Article in English | MEDLINE | ID: mdl-38963079

ABSTRACT

Loss-of-function (LoF) variants in the TANK binding kinase 1 (TBK1) gene are implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. In this study, we present the first familial cases of ALS and parkinsonism associated with a novel TBK1 variant. We describe two siblings: one diagnosed with classical ALS and the other with a unique syndrome overlapping ALS and parkinsonism. Comprehensive clinical and imaging evaluations supported these diagnoses. Genetic analysis through whole-genome sequencing revealed a previously unknown heterozygous splice site variant in TBK1. Functional assessments demonstrated that this splice site variant leads to abnormal splicing and subsequent degradation of the mutated TBK1 allele by nonsense-mediated decay, confirming its pathogenic impact. Our findings suggest a broader involvement of TBK1 in neurodegenerative diseases and underscore the need for further research into TBK1's role, advocating for screening for TBK1 variants in similar familial cases.

2.
Chemistry ; : e202401080, 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39039606

ABSTRACT

Inspired by the previous machine-learning study that the number of hydrogen-bonding acceptor (NHBA) is important index for the hole mobility of organic semiconductors, seven dithienobenzothiazole (DBT) derivatives 1a-g (NHBA = 5) were designed and synthesized by one-step functionalization from a common precursor. X-ray single-crystal structural analyses confirmed that the molecular arrangements of 1b (the diethyl and ethylthienyl derivative) and 1c (the di(n-propyl) and n-propylthienyl derivative) in the crystal are classified into brickwork structures with multidirectional intermolecular charge-transfer integrals, as a result of incorporation of multiple hydrogen-bond acceptors. The solution-processed top-gate bottom-contact devices of 1b and 1c had hole mobilities of 0.16 and 0.029 cm2 V-1s-1, respectively.

3.
J Am Chem Soc ; 146(32): 22699-22710, 2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39083719

ABSTRACT

Chiral molecular assemblies have attracted considerable attention because of their interesting physical properties, such as spin-selective electron transport. Cation-anion salts of three azolium cations, imidazolium (HIm+), triazolium (HTrz+), and thiazolium (HThz+), in combination with a chiral camphorsulfonate (1S-CS-) and their racemic compounds (rac-CS-) were prepared and compared in terms of phase transitions, crystal structures, dynamics of constituent molecules, dielectric responses, and proton conductivities. The cation-anion crystals containing HIm+ showed no significant difference in proton conductivity between the homochiral and racemic crystals, whereas the HTrz+-containing crystals showed higher proton conductivity and lower activation energy in the homochiral form than in the racemic form. A two-dimensional hydrogen-bonding network consisting of HTrz+ and -SO3- groups and similar in-plane rotational motion was observed in both crystals; however, the HTrz+ cation in the homochiral crystal exhibited the rotational motion modulated with translational motion, whereas the HTrz+ cation in the racemic crystal exhibited almost steady in-plane rotational motion. The different motional degrees of freedom were confirmed by crystal structure analyses and temperature- and frequency-dependent dielectric constants. In contrast, steady in-plane rotational motion with the thermally activated fluctuating motion of CS- was observed both in homochiral and racemic crystals containing HIm+, which averaged the motional space of protons resulting in similar dielectric responses and proton conductivities. The control of motional degrees of freedom in homochiral crystals affects the proton conductivity and is useful for the design of molecular proton conductors.

4.
PCN Rep ; 3(1): e181, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38868479

ABSTRACT

Background: To date, only a few reports of anti-LGI1 encephalitis with isolated psychiatric symptoms in the initial phase have been reported. We present a relatively rare case of antileucine-rich glioma-inactivated 1 (LGI1) encephalitis that developed only psychiatric symptoms at the onset. Case Presentation: The patient was a male in his 40s who developed anxiety and panic symptoms and was started on antidepressants after being diagnosed with panic disorder by a psychiatrist. He visited our hospital 2 months later presenting with hallucinations, delusions, mild cognitive decline, and faciobrachial dystonic seizures in the left upper extremity and face. Fluid-attenuated inversion recovery magnetic resonance imaging revealed swelling and hyperintensities in the right caudate nucleus and putamen. Cerebrospinal fluid analysis did not show increased protein levels or cell counts and revealed positive oligoclonal bands. Subsequently, positive results for anti-LGI1 antibodies were observed in the cerebrospinal fluid. Therefore, the patient was diagnosed with anti-LGI1 encephalitis. Conclusion: This case highlights the need to consider anti-LGI1 encephalitis therapy in patients with acute-onset psychiatric symptoms.

5.
Parkinsonism Relat Disord ; 124: 106992, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38701719

ABSTRACT

INTRODUCTION: Anti-immunoglobulin-like cell adhesion molecule 5 (IgLON5) disease is a rare autoimmune encephalitis that can mimic progressive supranuclear palsy or corticobasal syndrome. Moreover, anti-IgLON5 disease can present with symptoms characteristic of multiple system atrophy (MSA), such as cerebellar ataxia and autonomic dysfunction. However, the clinical features of anti-IgLON5 disease resembling MSA have not been well established. METHODS: We enrolled 35 patients with suspected MSA for whom anti-IgLON5 antibody tests were requested. We evaluated immunoglobulin G (IgG) against IgLON5 using cell-based assays. We also summarized the clinical characteristics of patients who were positive for anti-IgLON5 antibodies. RESULTS: We identified serum and cerebrospinal fluid anti-IgLON5 antibodies in three patients. These patients had many clinical features characteristic of MSA, including parkinsonism, cerebellar ataxia, severe orthostatic hypotension, acute respiratory failure, sleep parasomnia, vocal cord paralysis, and pyramidal tract signs. Clinical features atypical for MSA were myorhythmia, horizontal eye movement restriction, fasciculations, and painful muscle cramps. CONCLUSION: Anti-IgLON5 disease may be an important differential diagnosis of MSA. A comprehensive physical examination, including assessments of eye movement, lower motor neuron signs, and atypical involuntary movements, is important to avoid misdiagnosis.


Subject(s)
Autoantibodies , Cell Adhesion Molecules, Neuronal , Multiple System Atrophy , Humans , Multiple System Atrophy/diagnosis , Multiple System Atrophy/blood , Male , Female , Diagnosis, Differential , Aged , Middle Aged , Autoantibodies/blood , Autoantibodies/cerebrospinal fluid , Cell Adhesion Molecules, Neuronal/immunology
6.
Nat Commun ; 15(1): 3028, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38627402

ABSTRACT

Mixed-stack complexes which comprise columns of alternating donors and acceptors are organic conductors with typically poor electrical conductivity because they are either in a neutral or highly ionic state. This indicates that conductive carriers are insufficient or are mainly localized. In this study, mixed-stack complexes that uniquely exist at the neutral-ionic boundary were synthesized by combining donors (bis(3,4-ethylenedichalcogenothiophene)) and acceptors (fluorinated tetracyanoquinodimethanes) with similar energy levels and orbital symmetry between the highest occupied molecular orbital of the donor and the lowest unoccupied molecular orbital of the acceptor. Surprisingly, the orbitals were highly hybridized in the single-crystal complexes, enhancing the room-temperature conductivity (10-4-0.1 S cm-1) of mixed-stack complexes. Specifically, the maximum conductivity was the highest reported for single-crystal mixed-stack complexes under ambient pressures. The unique electronic structures at the neutral-ionic boundary exhibited structural perturbations between their electron-itinerant and localized states, causing abrupt temperature-dependent changes in their electrical, optical, dielectric, and magnetic properties.

7.
Angew Chem Int Ed Engl ; 63(24): e202404700, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38577718

ABSTRACT

The molecular conformation, crystalline morphology, and properties of photochromic organic crystals can be controlled through photoirradiation, making them promising candidates for functional organic materials. However, photochromic porous molecular crystals with a networked framework structure are rare due to the difficulty in maintaining space that allows for photo-induced molecular motion in the crystalline state. This study describes a photo-responsive single crystal based on hydrogen-bonded (H-bonded) network of dihydrodimethylbenzo[e]pyrene derivative 4BDHP. A crystal composed of H-bonded undulate layers, 4BDHP-2, underwent photo-isomerization in the crystalline state due to loose stacking of the layers. Particularly, enantio-pure crystal (S,S)-4BDHP-2 allowed to reveal the structure of the photoisomerized crystal, in which the closed form (4BDHP) and open form (4CPD) were arranged alternately with keeping crystalline periodicity, although side reactions were also implied. The present proof-of-concept system of a photochromic framework that retains crystalline periodicity after photo-isomerization may provide new light-driven porous functional materials.

8.
Article in English | MEDLINE | ID: mdl-38413129

ABSTRACT

PURPOSE: The objective of this study was to assess the performance of ChatGPT (GPT-4) on all items, including those with diagrams, in the Japanese National License Examination for Pharmacists (JNLEP) and compare it with the previous GPT-3.5 model's performance. METHODS: The 107th JNLEP, conducted in 2022, with 344 items input into the GPT-4 model, was targeted for this study. Separately, 284 items, excluding those with diagrams, were entered into the GPT-3.5 model. The answers were categorized and analyzed to determine accuracy rates based on categories, subjects, and presence or absence of diagrams. The accuracy rates were compared to the main passing criteria (overall accuracy rate ≥62.9%). RESULTS: The overall accuracy rate for all items in the 107th JNLEP in GPT-4 was 72.5%, successfully meeting all the passing criteria. For the set of items without diagrams, the accuracy rate was 80.0%, which was significantly higher than that of the GPT-3.5 model (43.5%). The GPT-4 model demonstrated an accuracy rate of 36.1% for items that included diagrams. CONCLUSION: Advancements that allow GPT-4 to process images have made it possible for LLMs to answer all items in medical-related license examinations. This study's findings confirm that ChatGPT (GPT-4) possesses sufficient knowledge to meet the passing criteria.


Subject(s)
Pharmacists , Humans , Japan
9.
Intern Med ; 63(15): 2187-2191, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38171876

ABSTRACT

Anti-IgLON5 disease shows various neurological manifestations, of which dysautonomia is one of the major symptoms and is rarely improved by immunotherapy. We herein report a patient with anti-IgLON5 disease who showed several autonomic failures, including vocal cord palsy for four months. The patient presented with cognitive impairments, bulbar symptoms accompanied by myorhythmia in the pharynx and tongue, cerebellar ataxia with tremor, motor neuron symptoms in the limbs, gastrointestinal dysfunction, orthostatic hypotension, non-rapid eye movement sleep disorder on polysomnography, and severe vocal cord palsy. Combined immunotherapy improved his symptoms, including vocal cord palsy, suggesting that combined immunotherapy might improve dysautonomia in anti-IgLON5 disease.


Subject(s)
Immunotherapy , Primary Dysautonomias , Vocal Cord Paralysis , Humans , Male , Primary Dysautonomias/etiology , Vocal Cord Paralysis/therapy , Vocal Cord Paralysis/etiology , Immunotherapy/methods , Cell Adhesion Molecules, Neuronal/immunology , Treatment Outcome , Middle Aged , Autoantibodies/blood , Autoantibodies/immunology
10.
Intern Med ; 63(6): 857-860, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-37587040

ABSTRACT

Paraneoplastic cerebellar degeneration (PCD) is a paraneoplastic neurological syndrome that is rarely accompanied by seropositivity with a combination of multiple antibodies. We herein report a 50-year-old man with PCD accompanied by small-cell lung cancer (SCLC). This patient was seropositive for anti-glutamic acid decarboxylase 65, anti-SRY-related HMG-box gene 1 and anti-voltage-gated calcium channel antibodies. After chemoradiation therapy without immunotherapy, cerebellar ataxia of the trunk and limbs markedly improved, along with a notable amelioration of SCLC. This case suggests that tumor therapy should be started immediately and that a panel of anti-neuronal antibodies should be evaluated when PCD with SCLC is suspected.


Subject(s)
Lung Neoplasms , Paraneoplastic Cerebellar Degeneration , Small Cell Lung Carcinoma , Male , Humans , Middle Aged , Lung Neoplasms/complications , Lung Neoplasms/therapy , Small Cell Lung Carcinoma/complications , Small Cell Lung Carcinoma/therapy , Antibodies , Chemoradiotherapy , Autoantibodies
11.
Adv Sci (Weinh) ; 10(29): e2207440, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37712117

ABSTRACT

Large-area single-crystalline thin films of n-type organic semiconductors (OSCs) fabricated via solution-processed techniques are urgently demanded for high-end electronics. However, the lack of molecular designs that concomitantly offer excellent charge-carrier transport, solution-processability, and chemical/thermal robustness for n-type OSCs limits the understanding of fundamental charge-transport properties and impedes the realization of large-area electronics. The benzo[de]isoquinolino[1,8-gh]quinolinetetracarboxylic diimide (BQQDI) π-electron system with phenethyl substituents (PhC2 -BQQDI) demonstrates high electron mobility and robustness but its strong aggregation results in unsatisfactory solubility and solution-processability. In this work, an asymmetric molecular design approach is reported that harnesses the favorable charge transport of PhC2 -BQQDI, while introducing alkyl chains to improve the solubility and solution-processability. An effective synthetic strategy is developed to obtain the target asymmetric BQQDI (PhC2 -BQQDI-Cn ). Interestingly, linear alkyl chains of PhC2 -BQQDI-Cn (n = 5-7) exhibit an unusual molecular mimicry geometry with a gauche conformation and resilience to dynamic disorders. Asymmetric PhC2 -BQQDI-C5 demonstrates excellent electron mobility and centimeter-scale continuous single-crystalline thin films, which are two orders of magnitude larger than that of PhC2 -BQQDI, allowing for the investigation of electron transport anisotropy and applicable electronics.

12.
J Am Chem Soc ; 145(35): 19177-19181, 2023 Sep 06.
Article in English | MEDLINE | ID: mdl-37623927

ABSTRACT

Multiple proton transfer (PT) controllable by external stimuli plays a crucial role in fundamental chemistry, biological activity, and material science. However, in crystalline systems, controlling multiple PT, which results in a distinct protonation state, remains challenging. In this study, we developed a novel tridentate ligand and iron(II) complex with a short hydrogen bond (HB) that exhibits a PT-coupled spin transition (PCST). Single-crystal X-ray and neutron diffraction measurements revealed that the positions of the two protons in the complex can be controlled by temperature and photoirradiation based on the thermal- and photoinduced PCST. The obtained results suggest that designing molecules that form short HBs is a promising approach for developing multiple PT systems in crystals.

13.
J Am Chem Soc ; 145(28): 15152-15161, 2023 Jul 19.
Article in English | MEDLINE | ID: mdl-37395785

ABSTRACT

Modern organic conductors are typically low-molecular-weight or polymer-based materials. Low-molecular-weight materials can be characterized using crystallographic information, allowing structure-conductivity relationships to be established and conduction mechanisms to be understood. However, controlling their conductive properties through molecular structural modulation is often challenging because of their relatively narrow conjugate areas. In contrast, polymer-based materials have highly π-conjugated structures with wide molecular-weight distributions, and their structural inhomogeneity makes characterizing their structures difficult. Thus, we focused on the less-explored intermediate, i.e., single-molecular-weight oligomers that model doped poly(3,4-ethylenedioxythiophene) (PEDOT). The dimer and trimer models provided clear structures; however, the short oligomers led to much lower conductivities (<10-3 S cm-1) than that of doped PEDOT. Herein, we elongated the oligomer to a tetramer through geometrical tuning based on a mixed sequence. The "P-S-S-P" sequence (S: 3,4-ethylenedithiothiophene; P: 3,4-(2',2'-dimethypropylenedioxy)thiophene) with twisted S-S enhanced the solubility and chemical stability. The subsequent oxidation process planarized the oligomer and expanded the conjugate area. Interestingly, the sequence involving sterically bulky outer P units allowed the doped oligomer to form a pitched π-stack in the single-crystal form. This enabled the inclusion of excess counter anions, which modulated the band filling. The combined effects of conjugate area expansion and band-filling modulation significantly increased the room-temperature conductivity to 36 S cm-1. This is the highest value reported for a single-crystalline oligomer conductor. Furthermore, a metallic state was observed above room temperature in a single-crystalline oligoEDOT for the first time. This unique mixed-sequence strategy for oligomer-based conductors enabled the precise control of conductive properties.

14.
Acta Crystallogr E Crystallogr Commun ; 79(Pt 6): 549-551, 2023 May 01.
Article in English | MEDLINE | ID: mdl-37288466

ABSTRACT

The reaction of 1-(4,5-dimeth-oxy-2,3-di-nitro-phen-yl)-2-methyl-propan-1-ol and butyl-iso-cyanate using di-butyl-tin dilaurate as a catalyst afforded 1-(4,5-dimeth-oxy-2,3-di-nitro-phen-yl)-2-methyl-propyl N-butyl-carbamate, C17H25N3O8, which released butyl-amine upon photoirradiation. Single crystals of the title compound were grown in a 1:1 mixed solution of hexane and ethyl acetate. Two nitro groups and one meth-oxy group are twisted out of the plane of the aromatic ring in the novel photo-protecting group. Inter-molecular hydrogen bonds are observed between N-butyl-carbamate moieties parallel to the a axis.

15.
Angew Chem Int Ed Engl ; 62(29): e202305747, 2023 Jul 17.
Article in English | MEDLINE | ID: mdl-37204160

ABSTRACT

Optically active, hyperbranched, poly(fluorene-2,4,7-triylethene-1,2-diyl) [poly(fluorenevinylene)] derivatives bearing a neomenthyl group and a pentyl group at the 9-position of the fluorene backbone at various ratios acted as a chirality donor (host polymers) efficiently included naphthalene, anthracene, pyrene, 9-phenylanthracene, and 9,10-diphenyanthracene as a chirality acceptor (guest molecules) in their interior space in film as well as in solution, with the guest molecules exhibiting intense circular dichroism through chirality transfer with chirality amplification. The efficiency of the chirality transfer was much higher with higher-molar-mass polymers than lower-molar-mass ones as well as with hyperbranched polymers compared to the analogous linear ones. The hyperbranched polymers include the small molecules in their complex structure without any specific interactions at various stoichiometries. The included molecules may have ordered intermolecular arrangement that may be somewhat similar to those of liquid crystals. Naphthalene, anthracene, and pyrene included in the polymer exhibited efficient circularly polarized luminescence, where the chirality was remarkably amplified in excited states, and anthracene exhibited especially high anisotropies in the emission on the order of 10-2 .

16.
Immunol Rev ; 317(1): 42-70, 2023 08.
Article in English | MEDLINE | ID: mdl-37035998

ABSTRACT

Among the phospholipase A2 (PLA2 ) superfamily, which typically catalyzes the sn-2 hydrolysis of phospholipids to yield fatty acids and lysophospholipids, the secreted PLA2 (sPLA2 ) family contains 11 isoforms in mammals. Individual sPLA2 s have unique enzymatic specificity toward fatty acids and polar heads of phospholipid substrates and display distinct tissue/cellular distributions, suggesting their distinct physiological functions. Recent studies using knockout and/or transgenic mice for a full set of sPLA2 s have revealed their roles in modulation of immunity and related disorders. Application of mass spectrometric lipidomics to these mice has enabled to identify target substrates and products of individual sPLA2 s in given tissue microenvironments. sPLA2 s hydrolyze not only phospholipids in the plasma membrane of activated, damaged or dying mammalian cells, but also extracellular phospholipids such as those in extracellular vesicles, microbe membranes, lipoproteins, surfactants, and dietary phospholipids, thereby exacerbating or ameliorating various diseases. The actions of sPLA2 s are dependent on, or independent of, the generation of fatty acid- or lysophospholipid-derived lipid mediators according to the pathophysiological contexts. In this review, we make an overview of our current understanding of the roles of individual sPLA2 s in various immune responses and associated diseases.


Subject(s)
Phospholipases A2, Secretory , Animals , Humans , Mice , Phospholipases A2, Secretory/metabolism , Fatty Acids , Mice, Transgenic , Cell Membrane/metabolism , Mammals/metabolism
17.
Phys Chem Chem Phys ; 25(17): 12394-12400, 2023 May 03.
Article in English | MEDLINE | ID: mdl-37092303

ABSTRACT

The application of single-crystal neutron diffraction (SCND) to observe proton-transfer phenomena in crystalline compounds exhibiting unusual protonation states or proton dynamics has garnered significant research interest in recent years. However, proton tautomerism, which results in different protonation states before and after proton transfer, has never been observed using the SCND technique. Thus, to observe the proton tautomerism phenomenon by SCND measurements, we developed an iron(II) complex that forms a large crystal and exhibits a proton-transfer-coupled spin transition (PCST). The presence of the two types of proton tautomers was determined by conventional analysis of the proton position by X-ray crystallography, infrared spectroscopy, and density functional theory calculations. Finally, our results confirmed that proton tautomerism was successfully observed for the first time using variable-temperature SCND measurements.

18.
Intern Med ; 62(23): 3541-3544, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37062729

ABSTRACT

The anti-GQ1b IgG antibody is often accompanied by other anti-ganglioside antibodies, which induces various neurological symptoms. We herein report a patient with anti-ganglioside antibodies, including anti-GQ1b IgG and anti-GT1a IgG antibodies, showing bilateral ophthalmoplegia, facial nerve palsies, dysarthria, dysphagia, dysesthesia in both hands, and enhancement of the bilateral oculomotor, abducens, and facial nerves on gadolinium (Gd)-enhanced T1-weighted brain magnetic resonance imaging (MRI). He was first treated with intravenous immunoglobulin, which improved ophthalmoplegia, bulbar palsies, and dysesthesia of hands, but the facial nerve palsies worsened, and Gd enhancement of the brain nerves persisted. High-dose methylprednisolone therapy subsequently improved the facial nerve palsies and Gd enhancement of the cranial nerves. This is the first case with anti-ganglioside antibodies presenting with multiple cranial nerve palsies that was followed to track the changes in the Gd enhancement of cranial nerves on MRI.


Subject(s)
Cranial Nerve Diseases , Facial Paralysis , Miller Fisher Syndrome , Ophthalmoplegia , Male , Humans , Gadolinium , Gangliosides , Paresthesia , Cranial Nerve Diseases/diagnostic imaging , Cranial Nerve Diseases/drug therapy , Cranial Nerve Diseases/complications , Immunoglobulins, Intravenous/therapeutic use , Facial Paralysis/complications , Ophthalmoplegia/complications , Magnetic Resonance Imaging , Miller Fisher Syndrome/diagnosis
19.
J Healthc Inform Res ; 7(1): 84-103, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36910914

ABSTRACT

Wrong dose, a common prescription error, can cause serious patient harm, especially in the case of high-risk drugs like oral corticosteroids. This study aims to build a machine learning model to predict dose-related prescription modifications for oral prednisolone tablets (i.e., highly imbalanced data with very few positive cases). Prescription data were obtained from the electronic medical records at a single institute. Cluster analysis classified the clinical departments into six clusters with similar patterns of prednisolone prescription. Two patterns of training datasets were created with/without preprocessing by the SMOTE method. Five ML models (SVM, KNN, GB, RF, and BRF) and logistic regression (LR) models were constructed by Python. The model was internally validated by five-fold stratified cross-validation and was validated with a 30% holdout test dataset. Eighty-two thousand five hundred fifty-three prescribing data for prednisolone tablets containing 135 dose-corrected positive cases were obtained. In the original dataset (without SMOTE), only the BRF model showed a good performance (in test dataset, ROC-AUC:0.917, recall: 0.951). In the training dataset preprocessed by SMOTE, performance was improved on all models. The highest performance models with SMOTE were SVM (in test dataset, ROC-AUC: 0.820, recall: 0.659) and BRF (ROC-AUC: 0.814, recall: 0.634). Although the prescribing data for dose-related collection are highly imbalanced, various techniques such as the following have allowed us to build high-performance prediction models: data preprocessing by SMOTE, stratified cross-validation, and BRF classifier corresponding to imbalanced data. ML is useful in complicated dose audits such as oral prednisolone. Supplementary Information: The online version contains supplementary material available at 10.1007/s41666-023-00128-3.

20.
Dalton Trans ; 52(11): 3295-3299, 2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36648316

ABSTRACT

Mononuclear oxovanadium(V) complexes [V(O)XL (1: X = Ot-Bu, 2: X = Cl)] [H2L: 2,2'-methylene bis(4,6-di-tert-butylphenol)(4'-tert-butyl-6'-(1-adamantyl)phenol)] directed towards asymmetric catalysis have been synthesised as racemic compounds using an unsymmetric and achiral phenolic bidentate ligand (H2L), and NMR and UV-vis absorption spectroscopies, single-crystal X-ray diffraction, and IR spectroscopy revealed their racemic chiral-at-vanadium structures in solution and in the crystal. In addition, theoretical calculations revealed that the HOMO-LUMO energy gap is smaller for unsymmetric ligands, which promotes d-orbital splitting of the metal centre.

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