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1. Engineering bistetrazoles: ( E )-5,5′-(ethene-1,2-diyl)bis(1 H -tetrazol-1-ol) as a new planar high-energy-density material

   https://doi.org/10.1039/d2ma00664b  

   Singh, Jatinder ; Staples, Richard J. ; Shreeve, Jean'ne M. ( July 2022 , Materials Advances)

   Energetic properties of bistetrazole derivatives are improved by the step-by-step introduction of functionalities which improve heat of formation, density, and oxygen content. The incorporation of unsaturation between bis(1 H -tetrazol-5-yl) and bis(1 H -tetrazol-1-ol) derivatives leads to planarity which enhances the density of the final product. In this manuscript, we have synthesized compounds 1,2-di(1 H -tetrazol-5-yl)ethane (4), ( E )-1,2-di(1 H -tetrazol-5-yl)ethene (5), and ( E )-5,5′-(ethene-1,2-diyl)bis(1 H -tetrazol-1-ol), (6) using readily available starting materials. Their corresponding dihydroxylammonium salts 7, 8 and 9 are obtained by reacting two equivalents of hydroxylamine (50% in water). New compounds are analyzed using IR, EA, DSC and multinuclear NMR spectroscopy ( 1 H, 13 C and 15 N). The solid-state structures of compounds 6, 7, 8 and 9 are confirmed by single-crystal X-ray diffraction. The energetic performances are calculated using the EXPLO5 (v6.06.02) code and the sensitivities towards external stimuli such as friction and impact are determined according to BAM standard. Compound 6 {( E )-5,5′-(ethene-1,2-diyl)bis(1 H -tetrazol-1-ol)} exhibits a surprisingly high density of 1.91 g cm −3 at 100 K (1.86 g cm −3 at 298 K). Its detonation velocity (9017 m s −1 ) is considerably superior to those of RDX (8795 m s −1 ), which suggests it is a competitive high-energy-density material. 

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2. A (2-(Pyrrolidin-1-yl)ethan-1-olate)(1-oxo-3-phenyl-1,4-dihydronaphthalen-2-olate) μ-Oxo-Bridged Dicopper(II) Dimeric Complex

   https://doi.org/10.3390/M1846  

   Artis, Rylan ; Padgett, Clifford W ; Musso, Kennedy ; Shank, Nathaniel ; Marks, Allison ; Quillian, Brandon ( September 2024 , Molbank)

   The reaction of 2-(1H-pyrrol-1-yl)ethanol with 3-hydroxyflavone in the presence of copper(II) bromide yielded a dimeric copper(II) complex, [μ-O-(κ2-O,O-flav)(κ2-N,O-2PEO)Cu]2 (1) (flav = 3-hydroxyflavonolate; 2PEO = 2-(1H-pyrrol-1-yl)ethanolate) with both the flav and 2PEO ligands bound to the copper(II) atom in a κ2-bonding mode. The dimer is held electrostatically by bridging oxygen atoms between two copper atoms. Complex 1 was characterized by single-crystal X-ray diffraction, infrared, and UV-Vis spectroscopy, elemental analysis, and melting point determination. The complex crystallizes in the monoclinic space group P21/n (14) with cell values of a = 11.85340(10) Å, b = 8.51480(10) Å, c = 23.8453(2) Å; β = 99.3920(10)°.

    

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3. 1-(Hex-5-en-1-yl)-4-{[3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidene]methyl}quinolin-1-ium iodide monohydrate

   https://doi.org/10.1107/S2414314622007970  

   Shank, Nathaniel ; Stadler, Andrea L. ; Barrett, Sean P. ; Padgett, Clifford W. ( August 2022 , IUCrData)

   The title thiazole orange derivative, bearing an alkene substituent, crystallized as a monohydrate of its iodide salt, namely, (Z)-1-(hex-5-en-1-yl)-4-{[3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidene]methyl}quinolin-1-ium iodide monohydrate, C₂₄H₂₅N₂S⁺·I⁻·H₂O. The packing features aromatic π-stacking and van der Waals interactions. The water molecule of crystallization interacts with the cation and anionviaO—H...N and O—H...I hydrogen bonds, respectively.

    

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4. ipso -Arylative polymerization as a route to π-conjugated polymers: synthesis of poly(3-hexylthiophene)

   https://doi.org/10.1039/C8PY00605A  

   Shih, Feng-Yang ; Tian, Sisi ; Gallagher, Nicholas ; Park, Young S. ; Grubbs, Robert B. ( January 2018 , Polymer Chemistry)

   ipso -Arylative cross-coupling with two 3-hexylthiophene derivatives, (5-bromo-4-hexylthiophen-2-yl)diphenylmethanol and 2-(5-bromo-4-hexylthiophen-2-yl)propan-2-ol, has been used to prepare poly(3-hexylhiophene) (P3HT) as a model conjugated polymer. P3HT with number-average molecular weights ranging from 8–20 kg mol −1 ( Đ 1.4–2.2) was prepared from 5-bromo-4-hexylthiophen-2-yl)diphenylmethanol with a Pd(OAc) 2 /PCy 3 /Cs 2 CO 3 catalyst system. Only oligomerization of 2-(5-bromo-4-hexylthiophen-2-yl)propan-2-ol ( M n ≈ 3 kg mol −1 ) was observed under similar conditions. Studies with model compounds suggest that side reactions involving end-group loss limit ultimate molecular weights. 

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5. Coordination-Induced Bond Weakening and Electrocatalytic Proton-Coupled Electron Transfer of a Ruthenium Verdazyl Complex

   https://doi.org/10.1021/acs.inorgchem.3c02775  

   Galvin, Conor M. ; Marron, Daniel P. ; Dressel, Julia M. ; Waymouth, Robert M. ( January 2024 , Inorganic Chemistry)

   Coordination of the leucoverdazyl ligand 2,4-diisopropyl-6-(pyridin-2-yl)-1,4-dihydro-1,2,4,5-tetrazin-3(2H)-one VdH to Ru significantly weakens the ligand’s N-H bond. Electrochemical measurements show that the metalated leucoverdazyl Ru(VdH)(acetylacetonate)2 RuVdH has a lower pKa (-5 units), BDFE (-7 kcal/mol), and hydricity (-22 kcal/mol) than the free ligand. DFT calculations suggest that the increased acidity is in part attributable to the stabilization of the conjugate base Vd-. When free, Vd- distorts to avoid an 8πe- antiaromatic state, but it remains planar when bound to Ru. Proton-coupled electron transfer (PCET) behavior is observed for both the free and metalated leucoverdazyls. PCET equilibrium between Vd radical and TEMPOH affords a VdH BDFE that is in good agreement with that obtained from electrochemical methods. RuVd exhibits electrocatalytic PCET donor behavior. Under acidic conditions, it reduces the persistent trityl radical ·CAr3 (Ar = p-tert-butylphenyl) to the corresponding triarylmethane HCAr3 via net 1e-/1H+ transfer from RuVdH. 

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