1
|
Sun X, Fu Q, Dai P, Zhang C, Xu R. Catalyzing Benzoxazine Polymerization with Titanium-Containing POSS to Reduce the Curing Temperature and Improve Thermal Stability. Molecules 2023; 28:5450. [PMID: 37513322 PMCID: PMC10384060 DOI: 10.3390/molecules28145450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/09/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Trisilanolphenyl-polyhedral oligomeric silsesquioxane titanium (Ti-Ph-POSS) was synthesized through the corner-capping reaction, and Ti-Ph-POSS was dispersed in benzoxazine (BZ) to prepare Ti-Ph-POSS/PBZ composite materials. Ti-Ph-POSS could catalyze the ring-opening polymerization (ROP) of BZ and reduce the curing temperature of benzoxazine. In addition, Ti immobilized on the Ti-Ph-POSS cage could form covalent bonds with the N or O atoms on polybenzoxazine, improving the thermal stability of PBZ. The catalytic activity of the Ti-Ph-POSS/BZ mixtures was assessed and identified through 1H nuclear magnetic resonance (1H-NMR) and Fourier-transform infrared (FTIR) analyses, while thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) were used to determine the thermal properties of the composite. It was found that PBZ exhibited a higher glass transition temperature (Tg) and better thermal stability when Ti-Ph-POSS was added. The curing behavior of the Ti-Ph-POSS/BZ mixtures showed that the initial (Ti) and peak (Tp) curing temperatures sharply decreased as the content of Ti-Ph-POSS and the heating rate increased. The curing kinetics of these Ti-Ph-POSS/BZ systems were analyzed using the Kissinger method, and the morphology of Ti-Ph-POSS/PBZ was determined via scanning electron microscopy (SEM). It was found that the Ti-Ph-POSS particles were well distributed in the composites. When the content exceeded 2 wt%, several Ti-Ph-POSS particles could not react with benzoxazine and were only dispersed within the PBZ matrix, resulting in aggregation of the Ti-Ph-POSS molecules.
Collapse
Affiliation(s)
- Xiaoyi Sun
- Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology, Ministry of Education, Beijing 100029, China
| | - Qixuan Fu
- Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology, Ministry of Education, Beijing 100029, China
| | - Pei Dai
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Caili Zhang
- Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics, College of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China
| | - Riwei Xu
- Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology, Ministry of Education, Beijing 100029, China
| |
Collapse
|
2
|
Bilyachenko AN, Gutsul EI, Khrustalev VN, Astakhov GS, Zueva AY, Zubavichus YV, Kirillova MV, Shul'pina LS, Ikonnikov NS, Dorovatovskii PV, Shubina ES, Kirillov AM, Shul'pin GB. Acetone Factor in the Design of Cu 4-, Cu 6-, and Cu 9-Based Cage Coppersilsesquioxanes: Synthesis, Structural Features, and Catalytic Functionalization of Alkanes. Inorg Chem 2022; 61:14800-14814. [PMID: 36059209 DOI: 10.1021/acs.inorgchem.2c02217] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The present study describes a new feature in the self-assembly of cagelike copperphenylsilsesquioxanes: the strong influence of acetone solvates on cage structure formation. By this simple approach, a series of novel tetra-, hexa-, or nonacoppersilsesquioxanes were isolated and characterized. In addition, several new complexes of Cu4 or Cu6 nuclearity bearing additional nitrogen-based ligands (ethylenediamine, 2,2'-bipyridine, phenanthroline, bathophenanthroline, or neocuproine) were produced. Single-crystal X-ray diffraction studies established molecular architectures of all of the synthesized products. Several coppersilsesquioxanes represent a novel feature of cagelike metallasilsesquioxane (CLMS) in terms of molecular topology. A Cu4-silsesquioxane complex with ethylenediamine (En) ligands was isolated via the unprecedented self-assembly of a partly condensed framework of silsesquioxane ligands, followed by the formation of a sandwich-like cage. Two prismatic Cu6 complexes represent the different conformers─regular and elliptical hexagonal prisms, "cylinders", determined by the different orientations of the coordinated acetone ligands ("shape-switch effect"). A heterometallic Cu4Na4-sandwich-like derivative represents the first example of a metallasilsesquioxane complex with diacetone alcohol ligands formed in situ due to acetone condensation reaction. As a selected example, the compound [(Ph6Si6O11)2Cu4En2]·(acetone)2 was explored in homogeneous oxidation catalysis. It catalyzes the oxidation of alkanes to alkyl hydroperoxides with hydrogen peroxide and the oxidation of alcohols to ketones with tert-butyl hydroperoxide. Radical species take part in the oxidation of alkanes. Besides, [(Ph6Si6O11)2Cu4En2]·(acetone)2 catalyzes the mild oxidative functionalization of gaseous alkanes (ethane, propane, n-butane, and i-butane). Two different model reactions were investigated: (1) the oxidation of gaseous alkanes with hydrogen peroxide to give a mixture of oxygenates (alcohols, ketones, or aldehydes) and (2) the carboxylation of Cn gaseous alkanes with carbon monoxide, water, and potassium peroxodisulfate to give Cn+1 carboxylic acids (main products), along with the corresponding Cn oxygenates. For these reactions, the effects of acid promoter, reaction time, and substrate scope were explored. As expected for free-radical-type reactions, the alkane reactivity follows the trend C2H6 < C3H8 < n-C4H10 < i-C4H10. The highest total product yields were observed in the carboxylation of i-butane (up to 61% based on i-C4H10). The product yields and catalyst turnover numbers (TONs) are remarkable, given an inertness of gaseous alkanes and very mild reaction conditions applied (low pressures, 50-60 °C temperatures).
Collapse
Affiliation(s)
- Alexey N Bilyachenko
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia.,Peoples' Friendship University of Russia, Miklukho-Maklay St., 6, 117198 Moscow, Russia
| | - Evgenii I Gutsul
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia
| | - Victor N Khrustalev
- Peoples' Friendship University of Russia, Miklukho-Maklay St., 6, 117198 Moscow, Russia.,Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia
| | - Grigorii S Astakhov
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia
| | - Anna Y Zueva
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia.,Peoples' Friendship University of Russia, Miklukho-Maklay St., 6, 117198 Moscow, Russia
| | - Yan V Zubavichus
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis SB RAS, Nikolskii prosp., 1, Koltsovo 630559, Russia
| | - Marina V Kirillova
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Lidia S Shul'pina
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia
| | - Nikolay S Ikonnikov
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia
| | - Pavel V Dorovatovskii
- National Research Center "Kurchatov Institute", Akademika Kurchatova pl., 1, 123182 Moscow, Russia
| | - Elena S Shubina
- A.N.Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street, 28, 119991 Moscow, Russia
| | - Alexander M Kirillov
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Georgiy B Shul'pin
- Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina, dom 4, Moscow 119991, Russia.,Chair of Chemistry and Physics, Plekhanov Russian University of Economics, Stremyannyi pereulok 36, Moscow 117997, Russia
| |
Collapse
|
3
|
Astakhov GS, Levitsky MM, Zubavichus YV, Khrustalev VN, Titov AA, Dorovatovskii PV, Smol'yakov AF, Shubina ES, Kirillova MV, Kirillov AM, Bilyachenko AN. Cu 6- and Cu 8-Cage Sil- and Germsesquioxanes: Synthetic and Structural Features, Oxidative Rearrangements, and Catalytic Activity. Inorg Chem 2021; 60:8062-8074. [PMID: 33979518 DOI: 10.1021/acs.inorgchem.1c00586] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study reports intriguing features in the self-assembly of cage copper(II) silsesquioxanes in the presence of air. Despite the wide variation of solvates used, a series of prismatic hexanuclear Cu6 cages (1-5) were assembled under mild conditions. In turn, syntheses at higher temperatures are accompanied by side reactions, leading to the oxidation of solvates (methanol, 1-butanol, and tetrahydrofuran). The oxidized solvent derivatives then specifically participate in the formation of copper silsesquioxane cages, allowing the isolation of several unusual Cu8-based (6 and 7) and Cu6-based (8) complexes. When 1,4-dioxane was applied as a reaction medium, deep rearrangements occurred (with a total elimination of silsesquioxane ligands), causing the formation of mononuclear copper(II) compounds bearing oxidized dioxane fragments (9 and 11) or a formate-driven 1D coordination polymer (10). Finally, a "directed" self-assembly of sil- and germsesquioxanes from copper acetate (or formate) resulted in the corresponding acetate (or formate) containing Cu6 cages (12 and 13) that were isolated in high yields. The structures of all of the products 1-13 were established by single-crystal X-ray diffraction, mainly based on the use of synchrotron radiation. Moreover, the catalytic activity of compounds 12 and 13 was evaluated toward the mild homogeneous oxidation of C5-C8 cycloalkanes with hydrogen peroxide to form a mixture of the corresponding cyclic alcohols and ketones.
Collapse
Affiliation(s)
- Grigorii S Astakhov
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (RAS), Vavilov Strasse 28, Moscow 119991, Russia.,Peoples' Friendship University of Russia, Miklukho-Maklay Street 6, Moscow 117198, Russia
| | - Mikhail M Levitsky
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (RAS), Vavilov Strasse 28, Moscow 119991, Russia
| | - Yan V Zubavichus
- Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences (SB RAS) Prosp. Akad., Lavrentieva 5, Novosibirsk 630090, Russia
| | - Victor N Khrustalev
- Peoples' Friendship University of Russia, Miklukho-Maklay Street 6, Moscow 117198, Russia.,Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences (RAS), Leninsky Prospect 47, Moscow 119991, Russia
| | - Aleksei A Titov
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (RAS), Vavilov Strasse 28, Moscow 119991, Russia
| | - Pavel V Dorovatovskii
- National Research Center "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow 123182, Russia
| | - Alexander F Smol'yakov
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (RAS), Vavilov Strasse 28, Moscow 119991, Russia.,Plekhanov Russian University of Economics, Stremyanny per. 36, Moscow 117997, Russia
| | - Elena S Shubina
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (RAS), Vavilov Strasse 28, Moscow 119991, Russia
| | - Marina V Kirillova
- Centro de Química Estrutural and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, Lisbon 1049-001, Portugal
| | - Alexander M Kirillov
- Centro de Química Estrutural and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, Lisbon 1049-001, Portugal
| | - Alexey N Bilyachenko
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (RAS), Vavilov Strasse 28, Moscow 119991, Russia
| |
Collapse
|