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1. Synthesis and Characterizations of 5,5′‐Bibenzo[ rst ]pentaphene with Axial Chirality and Symmetry‐Breaking Charge Transfer

   https://doi.org/10.1002/advs.202200004  

   Xu, Xiushang ; Gunasekaran, Suman ; Renken, Scott ; Ripani, Lorenzo ; Schollmeyer, Dieter ; Kim, Woojae ; Marcaccio, Massimo ; Musser, Andrew ; Narita, Akimitsu ( February 2022 , Advanced Science)

   Exploration of novel biaryls consisting of two polycyclic aromatic hydrocarbon (PAH) units can be an important strategy toward further developments of organic materials with unique properties. In this study, 5,5′‐bibenzo[rst]pentaphene (BBPP) with two benzo[rst]pentaphene (BPP) units is synthesized in an efficient and versatile approach, and its structure is unambiguously elucidated by X‐ray crystallography. BBPP exhibits axial chirality, and the (M)‐ and (P)‐enantiomers are resolved by chiral high‐performance liquid chromatography and studied by circular dichroism spectroscopy. These enantiomers have a relatively high isomerization barrier of 43.6 kcal mol⁻¹calculated by density functional theory. The monomer BPP and dimer BBPP are characterized by UV‐vis absorption and fluorescence spectroscopy, cyclic voltammetry, and femtosecond transient absorption spectroscopy. The results indicate that both BPP and BBPP fluoresce from a formally dark S₁electronic state that is enabled by Herzberg–Teller intensity borrowing from a neighboring bright S₂state. While BPP exhibits a relatively low photoluminescence quantum yield (PLQY), BBPP exhibits a significantly enhanced PLQY due to a greater S₂intensity borrowing. Moreover, symmetry‐breaking charge transfer in BBPP is demonstrated by spectroscopic investigations in solvents of different polarity. This suggests high potential for singlet fission in suchπ‐extended biaryls through appropriate molecular design.

    

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2. Administration of alendronate exacerbates ammonium chloride-induced acidosis in mice

   https://doi.org/10.1371/journal.pone.0291649  

   Moody, Mikayla ; Schmidt, Tannin A. ; Trivedi, Ruchir ; Deymier, Alix ( September 2023 , PLOS ONE)

   Shah, Furqan A. (Ed.)

   Bone disease is highly prevalent in patients with chronic kidney disease (CKD), leading to an increased risk of bone fractures. This is due in part to metabolic acid-induced bone dissolution. Bisphosphonates (BPPs) are a potential treatment for inhibiting bone dissolution; however, there are limited studies observing the use of BPPs on acidotic patients. We aimed to determine efficacy of BPPs on maintaining bone health and pH regulation in acid-exposed mice. Using a diet-induced murine model of metabolic acidosis, we examined bone structure, composition, and mechanics as well as blood gases for three groups: control, acidosis, and acidosis + bisphosphonates (acidosis+BPP). Acidosis was induced for 14 days and alendronate was administered every 3 days for the acidosis+BPP group. The administration of BPP had little to no effect on bone structure, mechanics, and composition of the acidosis bones. However, administration of BPP did cause the mice to develop more severe acidosis than the acidosis only group. Overall, we discovered that BPPs may exacerbate acidosis symptoms by inhibiting the release of buffering ions from bone. Therefore, we propose that BPP administration should be carefully considered for those with CKD and that alkali supplementation could help minimize acidifying effects. 

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3. Optimization of crystal packing in semiconducting spin-crossover materials with fractionally charged TCNQ δ− anions (0 δ < 1)

   https://doi.org/10.1039/D1SC02843J  

   Üngör, Ökten ; Choi, Eun Sang ; Shatruk, Michael ( August 2021 , Chemical Science)

   Co-crystallization of the prominent Fe( ii ) spin-crossover (SCO) cation, [Fe(3-bpp) 2 ] 2+ (3-bpp = 2,6-bis(pyrazol-3-yl)pyridine), with a fractionally charged TCNQ δ − radical anion has afforded a hybrid complex [Fe(3-bpp) 2 ](TCNQ) 3 ·5MeCN (1·5MeCN, where δ = −0.67). The partially desolvated material shows semiconducting behavior, with the room temperature conductivity σ RT = 3.1 × 10 −3 S cm −1 , and weak modulation of conducting properties in the region of the spin transition. The complete desolvation, however, results in the loss of hysteretic behavior and a very gradual SCO that spans the temperature range of 200 K. A related complex with integer-charged TCNQ − anions, [Fe(3-bpp) 2 ](TCNQ) 2 ·3MeCN (2·3MeCN), readily loses the interstitial solvent to afford desolvated complex 2 that undergoes an abrupt and hysteretic spin transition centered at 106 K, with an 11 K thermal hysteresis. Complex 2 also exhibits a temperature-induced excited spin-state trapping (TIESST) effect, upon which a metastable high-spin state is trapped by flash-cooling from room temperature to 10 K. Heating above 85 K restores the ground-state low-spin configuration. An approach to improve the structural stability of such complexes is demonstrated by using a related ligand 2,6-bis(benzimidazol-2′-yl)pyridine (bzimpy) to obtain [Fe(bzimpy) 2 ](TCNQ) 6 ·2Me 2 CO (4) and [Fe(bzimpy) 2 ](TCNQ) 5 ·5MeCN (5), both of which exist as LS complexes up to 400 K and exhibit semiconducting behavior, with σ RT = 9.1 × 10 −2 S cm −1 and 1.8 × 10 −3 S cm −1 , respectively. 

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4. Identifying dynamic functional connectivity biomarkers using GIG‐ICA: Application to schizophrenia, schizoaffective disorder, and psychotic bipolar disorder

   https://doi.org/10.1002/hbm.23553  

   Du, Yuhui ; Pearlson, Godfrey D. ; Lin, Dongdong ; Sui, Jing ; Chen, Jiayu ; Salman, Mustafa ; Tamminga, Carol A. ; Ivleva, Elena I. ; Sweeney, John A. ; Keshavan, Matcheri S. ; et al ( March 2017 , Human Brain Mapping)

   Functional magnetic resonance imaging (fMRI) studies have shown altered brain dynamic functional connectivity (DFC) in mental disorders. Here, we aim to explore DFC across a spectrum of symptomatically‐related disorders including bipolar disorder with psychosis (BPP), schizoaffective disorder (SAD), and schizophrenia (SZ). We introduce a group information guided independent component analysis procedure to estimate both group‐level and subject‐specific connectivity states from DFC. Using resting‐state fMRI data of 238 healthy controls (HCs), 140 BPP, 132 SAD, and 113 SZ patients, we identified measures differentiating groups from the whole‐brain DFC and traditional static functional connectivity (SFC), separately. Results show that DFC provided more informative measures than SFC. Diagnosis‐related connectivity states were evident using DFC analysis. For the dominant state consistent across groups, we found 22 instances of hypoconnectivity (with decreasing trends from HC to BPP to SAD to SZ) mainly involving post‐central, frontal, and cerebellar cortices as well as 34 examples of hyperconnectivity (with increasing trends HC through SZ) primarily involving thalamus and temporal cortices. Hypoconnectivities/hyperconnectivities also showed negative/positive correlations, respectively, with clinical symptom scores. Specifically, hypoconnectivities linking postcentral and frontal gyri were significantly negatively correlated with the PANSS positive/negative scores. For frontal connectivities, BPP resembled HC while SAD and SZ were more similar. Three connectivities involving the left cerebellar crus differentiated SZ from other groups and one connection linking frontal and fusiform cortices showed a SAD‐unique change. In summary, our method is promising for assessing DFC and may yield imaging biomarkers for quantifying the dimension of psychosis.Hum Brain Mapp 38:2683–2708, 2017. ©2017 Wiley Periodicals, Inc.

    

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5. meso -Alkylidenyl dibenzihexaphyrins: synthesis and protonation studies

   https://doi.org/10.1039/c9cc04607k  

   Hong, Seong-Jin ; Dutta, Ranjan ; Kumar, Ravi ; He, Qing ; Lynch, Vincent M. ; Sessler, Jonathan L. ; Lee, Chang-Hee ( August 2019 , Chemical Communications)

   The synthesis and characterization of the alkylidenyl-dibenzihexaphyrins bearing four indanedionyl groups at the meso -positions linked via four meso -exocyclic double bonds is reported. Treatment with trifluoroacetic acid at 50 °C leads to C(α)-protonation of the two indanedionyl groups resulting increased macrocyclic conjugation with dramatic red shifted absorption spectra. 

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