A series of C,C-diacetylenic phosphaalkenes 1b-e has been prepared from 1-chloropenta-1,2-dien-4-ynes 6b-e in a reaction with Mes*PCl(2) (Mes* = 2,4,6-((t)Bu)(3)Ph) in the presence of LDA. Under identical conditions, isomeric butadiyne-substituted phosphaalkenes 2c-f can be obtained from 3-chloropenta-1,4-diynes 5c-f. The title compounds represent rare examples of diethynylethenes in which a constituting methylene has been replaced by a phosphorus center. The formation of both isomers can be rationalized by a common pathway that involves isomeric allenyllithium species. Spectroscopic, electrochemical, and theoretical investigations show that the phosphorus heteroatoms are an intrinsic part of the compounds' pi-systems and lead to decreased HOMO-LUMO gaps compared to those in all-carbon-based reference compounds.

Phosphaalkene inclusion at the periphery of acetylenic arenes results in decreased band gaps of the title compounds as verified by spectroscopic and electrochemical techniques. The electronic coupling between two 1-phosphahex-1-ene-3,5-diyne units is mediated by all para-substituted arenes and increases from 4b to 4d.

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Two two‐dimensional supramolecular Nickel(II) and Cobalt(III) complexes, [Ni(L2)2]·2CH3OH (1) and [2Co(L2)2] (2) (HL2 = 1‐(2‐{[(E)‐3‐bromo‐5‐chloro‐2‐hydroxybenzylidene]amino}phenyl)ethanone oxime), were synthesized via complexation of salts acetate with HL1 (2‐(3‐bromo‐5‐chloro‐2‐hydroxyphenyl)‐4‐methyl‐1,2‐dihydroquinazoline 3‐oxide, H is the deprotonatable hydrogen). During the reaction, the C–N bond in HL1 is converted into the C=N–OH group in HL2. The spectroscopic data of both complexes were compared with the ligand HL1. HL1 and both complexes were determined by single‐crystal X‐ray crystallography. The differently geometric features of the obtained complexes 1 and 2 are observed. In the crystal structure, 1 and 2 form an infinite 1‐D chain‐like and 2‐D supramolecular frameworks. EPR spectroscopy of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied. In addition, the calculated HOMO and LUMO energies show the character of HL1, complexes 1 and 2. The electronic transitions and spectral features of HL1 and both complexes were discussed by TD‐DFT calculations.

Commercialization of lithium ion batteries has accelerated dramatically over the last few decades. Single‐layered Ti3C2 (s‐Ti3C2) is effectively prepared by etching Ti3AlC2 via simple treatment with HCl and LiF, producing inevitably sediments always discarded after etching. This study explores the effect of LiF doping of multilayered Ti3C2 to form m‐Ti3C2/LiF consisting essentially of the sediments. Simple half‐cells assembled with m‐Ti3C2/LiF sediments suggest that LiF suppresses electrode volume expansion and surface cracking during cycling promoting Li+ intercalation/deintercalation. The data also suggest that LiF promotes formation of stable artificial solid electrolyte interfaces to prevent electrolyte and electrode degradation. The capacity of m‐Ti3C2/LiF sediments derived cells maintains 136 mAh g−1 after 1500 cycles at 300 mA g−1 while s‐Ti3C2 from supernatants physically mixed with 20 wt% LiF shows a capacity of 335 mAh g−1 (100th cycle) at 100 mA g−1 with an initial coulombic efficiency of 83%. Half‐cell anodes made of Ti3C2 etched by HF, commercial TiO2, and Sn powder mixed physically with 20 wt% LiF exhibit improved performance with cycling. These results indicate that the always discarded sediments can be directly used in LIBs and simple doping with LiF obviously improves the electrochemical performance of materials.