Organic materials have obtained unprecedented attention as emerging electrodes for sodium-ion batteries (SIBs), but they suffer from poor cycling stability and rate performance. Herein, we develop a simple strategy via locking the coplanarity to tune the electron and ion transport in linear polyimide for sodium-ion batteries. From unlocked and flexible molecular chain to spatially locked molecular chain, the polyimide cathodes possess better structural stability and higher electronic conductivity, exhibiting better cycling stability and higher reversible capacity. Moreover, the locked-in coplanar conformation endows the polyimide cathode with large surface area and rich porosity, leading to a rapid ion transport, which synergizes with the good electronic conductivity to improve the rate performance of the SIBs. As a result, the optimized polyimide electrode displays high capacity retentions of 99% after 100 cycles at 50 mA·g^–1 and 100% after 3000 cycles at 1000 mA·g^–1. This work expands the palette to design organic electrodes for high-performance SIBs.

Direct C(sp³)−H alkylation of alkylpyridines provides an efficient route to C(sp³)-rich pyridine motifs, which are highly prevalent in pharmaceuticals and agrochemicals. While numerous ionic methods have been developed, they typically require strong bases, elevated temperatures, or pre-functionalized substrates. To circumvent these limitations, photocatalytic methods relying on radical reactions have emerged, however, pre-activation of the substrates is required or the olefin scope is limited. Here, we report a visible light photocatalytic strategy for pyridylic C(sp³)−H alkylation via in situ borane exchange between pyridine substrates and triphenylphosphine-borane. This method operates under mild conditions, avoids the need for strong bases or metal catalysts, and accommodates both styrenes and unactivated olefins as coupling partners. Mechanistic studies revealed that borane exchange enhances the acidity of the C(sp³)−H bonds, thereby enabling rapid deprotonation to form a pyridylic carbanion intermediate. Subsequent single-electron oxidation by the oxidized form of the photocatalyst (PC) then generates the key pyridylic radical intermediate, which adds to olefins to generate another carbon-centered radical. Final hydrogen atom transfer from an arylthiol affords the desired product in good yields.

Conventional lithium-ion batteries that utilize high melting point ethylene carbonate (EC) solvent and graphite anodes exhibit a narrow operating temperature range, which is insufficient to meet the wide-temperature requirements of electric vehicle power batteries. Herein, a novel electrolyte featuring an anion-enriched solvation structure is developed by incorporating ethyl difluoroacetate (DFAE), a fluorinated solvent with wide liquid range and weak solvation capability, which enables the stable operation of lithium metal batteries (LMBs) over a broad temperature range (–50 °C to 60 °C). The anion-enrich solvation structure facilitates rapid desolvation and enables the formation of inorganic-dominated interphases on both the cathode and anode surfaces. NMC811||DEF||Li cells exhibit a high specific capacity of 194.7 mAh·g^–1 at a 2 C rate and room temperature, retaining 77.16% capacity after 400 cycles. The pouch cell using DEF electrolyte successfully powered an LED panel at –50 °C, demonstrating practical viability. This innovative strategy provides a promising pathway for the development of next generation wide-temperature LMBs.

Herein, we report a visible-light-mediated chemo- and regio-selective installation of N and S groups onto alkynes to afford 1,2-disubstituted alkane derivatives through sequential thiol-yne click chemistry and hydroamidation of alkynes with arylthiophenols and sulfonyl azides. This transformation proceeds efficiently under mild conditions with broad substrate scope, accommodating both aromatic and aliphatic alkynes. Central to this approach is the selective activation of the aryl vinyl thioether intermediate with the excited photocatalyst via triplet-triplet energy transfer (EnT) strategy to reach its excited state, which subsequently undergoes hydrogen atom transfer (HAT) with C⁴−H bond of Hantzsch ester (HE) to result in a benzyl radical intermediate and the corresponding HE^• radical. Afterwards, these two radical species could react with sulfonyl azides, respectively, to individually yield the desired product of double hydrofunctionalization of alkynes. The afforded HE^• radical species could involve in the radical chain mechanism to furnish the product according to a combined experimental and computational study. The origins of selectivity for this reaction are also rationalized. This work establishes an alternative photocatalytic approach to tackling the challenges in selectively realizing the difunctionalization of alkynes to access 1,2-diheteroatom-substituted alkanes under mild conditions.

Photocatalytic synthesis of hydrogen peroxide (H₂O₂) in systems integrating efficient catalytic reactions, product separation, and in situ collection remains a tremendous challenge. Herein, we report one-pot synthesis of anthraquinone (AQ)-functionalized UiO-66(NH₂) exhibiting exceptional photocatalytic H₂O₂ production rate of 44.8 mmol·g^–1·h^–1 (80.6 times higher than that of UiO-66(NH₂)) under visible light and 191 mmol·g^–1·h^–1 under simulated sunlight, coupled with 96% selectivity for benzyl alcohol (BA) oxidation to value-added benzaldehyde (BzH). The designed photocatalyst can be selectively dispersed in H₂O/BA biphasic interface, enabling spontaneous phase segregation of photogenerated H₂O₂ and BzH for autonomous product separation and continuous collection without external energy. Notably, a remarkable cumulative concentration of 681.6 mM (5452.8 μmol) was attained within 14 h. The results showcase that AQ integration enhances oxygen adsorption and establishes a robust built-in electric field (IEF) between UiO-66(NH₂) and AQ to drive efficient charge separation, facilitating the generation of abundant electrophilic singlet oxygen (¹O₂) via energy transfer (EnT) process. Mechanistic analysis reveals an unconventional H₂O₂ synthesis pathway, in which the generated ¹O₂ is subsequently reduced by electrons to superoxide radicals (•O₂^–), which then couple with protons to yield H₂O₂. This strategy offers a sustainable route for concurrent H₂O₂ and value-added chemical production.

Dimerization of small-molecule acceptors (SMAs) is an effective strategy to suppress molecular diffusion and enhance the stability of organic solar cells (OSCs), yet many dimerized SMAs (DSMAs) suffer from twisted backbones due to nonplanar SMA units and rotatable σ-bonds, limiting molecular packing and charge transport. Here, two dimerized M-series SMAs, DMS and DMSe, were designed by combining fluorinated central indanone units with thiophene or selenophene π-bridges to modulate backbone planarity and intermolecular packing. The selenophene-linked DMSe exhibits stronger intramolecular noncovalent interactions, resulting in enhanced backbone planarity, tighter π-π stacking, improved charge transport, and favorable phase-separated morphology. When blended with PM6, DMSe-based OSCs achieve a power conversion efficiency of 18.01%, surpassing 17.12% for DMS-based counterparts, while also demonstrating superior thermal and photostability. The improved performance is attributed to higher exciton dissociation, more balanced charge carrier mobilities, and increased face-on molecular orientation. These results highlight the critical role of synergistic π-bridge and central end-group engineering in modulating dimer geometry, optimizing blend morphology, and enhancing device performance and stability.

With the growing emphasis on green and sustainable development, the development of low-energy, environmentally friendly intelligent responsive materials has become an important direction. Among these, hydrochromic molecular switches have attracted considerable attention in recent years due to their mild stimulus (water), excellent reversibility, and ease of integration with other systems. These attributes make them particularly suitable for applications such as rewritable paper, smart labels, and environmental sensors. However, most existing molecular switches exhibit only a single visible absorption band, which inherently restricts their chromatic versatility and necessitates multi-dye blending to achieve multicolor outputs. To overcome this limitation, we present a rational molecular design strategy based on asymmetric amino modification of fluoran derivatives. By introducing distinct electron- donating and hydrophilic amino groups at the asymmetric 2- and 6-positions of the xanthene ring, we successfully constructed a series of high-performance hydrochromic molecular switches (M1–M3). Upon exposure to water, these molecules undergo a complete ring-opening isomerization, giving rise to intramolecular dual absorption in the visible region with peak separations exceeding 100 nm. Control experiments and theoretical calculations reveal that the two absorption bands originate from different localized π–π* transitions within the xanthene core, and critically depend on the 2-position amino substituent to activate the higher-energy transition channel. This unique electronic architecture enables precise color-switching behavior, yielding three distinct macroscopic colors: magenta, dark green, and purple-black. These hydrochromic molecular switches, when immobilized on solid substrates, demonstrate excellent reversibility over more than 50 write–erase cycles and maintain high optical contrast. Furthermore, they are fully compatible with water-jet printing, allowing for high-resolution, multicolor patterning on cellulose-based media for rewritable paper applications. This work not only provides a simple and efficient route to multicolor hydrochromism but also establishes asymmetric amino modification as a general principle for engineering intramolecular dual absorption, offering a new perspective for the molecular design and precise color regulation of next-generation stimuli-responsive dyes.

α-Nitroketones represent an important class of organic compounds in synthetic chemistry because of the synergistic interaction between their adjacent carbonyl and nitro functional groups. However, current reporting methods often pose environmental concerns and require harsh reaction conditions, such as the use of noble metal catalysts and external oxidants. Herein, we report a novel and environmentally benign electrochemical bifunctional groups strategy for the efficient synthesis of α-nitroketones directly from olefins. This approach is based on a dual-source system, in which Fe(NO₃)₃·9H₂O serves as a versatile precursor, simultaneously supplying the nitro group, while trace amounts of water inherently present in the electrolyte act as the oxygen source for carbonyl formation. This tandem oxidation–nitration process enables the direct construction of the valuable α-nitroketone scaffold from simple starting materials in a single operational step. A primary advantage of this methodology lies in its inherently green and sustainable nature. Compared with conventional methods, this strategy markedly decreases the necessity of using hazardous and volatile nitromethane as a nitro source and avoids the routine application of stoichiometric condensation or oxidizing agents that tend to produce large quantities of chemical waste. Instead, electricity functions as a traceless redox agent, driving the transformation under mild conditions—generally at room temperature or with minimal heating and under ambient pressure. This leads to a significantly reduced environmental footprint and enhances operational safety. The reaction demonstrates remarkable synthetic utility, characterized by a broad substrate scope. A wide variety of olefins, including those bearing aryl, aliphatic, and heterocyclic substituents, are smoothly converted into the corresponding α-nitroketones in moderate to good yields. In summary, we have developed a mild, efficient, and sustainable electrochemical route to α-nitroketones. By integrating atom-economic principles with the advantages of electrosynthesis—including inherent safety and scalability—this work provides a powerful and practical alternative to conventional methods, aligning with the growing demands of modern green chemistry.

The origin of a transformation's stereoselectivity is one of the core issues in asymmetric catalysis. Herein, we propose a general competitive induction model for predicting stereoselectivity in dual transition-metal-NHC asymmetric catalysis. This model is demonstrated to explore the origin of stereoselectivity for the asymmetric synthesis of spirooxindoles by Cu(I)/NHC-catalysed [3+3] annulation. Computational studies suggest a mechanism involving deprotonation, Brønsted-acid-assisted decarboxylation, nucleophilic addition, cyclic esterification, and protonation. Our studies suggest that nucleophilic addition is the reversible stereocenter-generating step, while subsequent irreversible cyclic esterification is the stereoselectivity-determining step. The metal-coordinated chiral NHC ligand and the NHC organocatalyst work together to induce chirality in the stereocenter-generating step. In the subsequent stereoselectivity-determining step, the NHC ligand is innocent due to its long distance from the reaction site. Thus, the stereoselectivity is fully determined by the NHC organocatalyst. This constitutes a significant difference from the widely proposed synergistic induction model. This competitive induction model elucidates how the two chiral sources govern stereoselectivity in the stereocenter-generating and stereoselectivity-determining steps, providing valuable insights for the rational design of cooperative asymmetric catalyst systems.

Open-shell radicals, susceptible to quenching by self-coupling, have found numerous practical applications in materials science and the medical field due to their high reactivity and rich photophysical and electronic properties. Porous and highly customisable crystalline frameworks, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), are ideal platforms for hosting radicals while suppressing their self-coupled annihilation. Yet, current strategies for introducing persistent radicals into these frameworks involve the benzannulation of sterically bulky alkyne-rich motifs and post-synthetic addition to alkyne moieties, which in turn compromise the porosity and crystallinity of the frameworks. Herein, a simple backfolded alkyne-rich diamine-terminated linker was designed and allowed to form a stable 2D COF, BF-COF. Upon facile thermocyclisation, radical-rich BF-COF-300 was obtained with retained crystallinity and porosity as well as far intense and wider light absorption than the primitive BF-COF. These also feature BF-COF-300 as a better candidate than BF-COF in both photothermal conversion and photocatalytic thioether oxidation.

Borane catalysis, pioneered by BEt₃, is a powerful method for the ring-opening polymerization (ROP) of epoxides and (co)polymerization of epoxides to generate diverse kinds of polymers. Among these systems, pre-organized dinuclear boranes are highly effective due to cooperative effects. However, current examples are limited to ammonium, phosphonium, and silicon-based structures, restricting the exploration of their structure-performance relationships. Herein, malonate esters were used as precursors to synthesize preorganized dinuclear boron catalysts QC-B1 and QC-B2. These catalysts were combined with tetrabutylammonium carbonate, and the resulting binary systems were investigated for their application in the ROP of propylene oxide (PO). The QC-B1/TBAC exhibited living and controllable characteristics in the ROP of PO and showed good tolerance toward chain transfer agents (CTAs), with one boron center tolerating up to 50 equivalents of CTA. Kinetic studies show the polymerization mechanism depends on the initiator: a mono-initiator leads to intramolecular chain growth, while a dual-initiator favors an intermolecular pathway.

A series of tetranuclear organotin clusters (Sn-mCl, Sn-opy, Sn-mMe, and Sn-dMe) with different carboxylate ligands (mCl, meta-chloromethylbenzoate; opy, picolinate; mMe, meta-methylbenzoate; dMe, 3,5-dimethylbenzoate) were synthesized and characterized. Evaluations on thermostability and film-forming capability demonstrate the potential of Sn-opy cluster and the mixture of Sn-opy with Sn-mCl cluster additive (m₁/m₂ = 9 : 1, designated as Resist-91) as negative-tone non-chemically amplified resist (n-CAR) materials. The lithographic performances of Resist-91 and Sn-opy resist were evaluated by using electron beam lithography. Sn-opy resist can only resolve the best 22 nm half-pitch (HP) pattern at 2000 μC·cm^–2. Resist-91 exhibits superior lithographic performance and resolves 20 nm HP patterns at 1450 μC·cm^–2, demonstrating a significantly improving of the sensitivity and resolution by the introduction of Sn-mCl. Further extreme ultraviolet lithography demonstrates the capability of Resist-91 to form 20 nm HP patterns at a dose of 39 mJ·cm^–2, with the best Z-factor of 2.1 × 10^–7 mJ·nm³ among ladder-shaped tetranuclear organotin resists. Extensive mechanistic analysis of Resist-91 and model films demonstrates the substitution of Cl atom by pyridine ligand, and the generation of a network consisting of tin oxides and organics with the assistance of Sn-mCl cluster, highlighting the critical role of additives with active ligands.

Organic solar cells (OSCs) leveraging non-fullerene acceptors (NFAs) have achieved power conversion efficiencies (PCEs) exceeding 20%, yet their performance critically depends on the nanoscale morphology of the bulk heterojunction (BHJ). Ternary blending is a promising strategy for enhancing photovoltaic parameters and morphology control, but simultaneously optimizing phase separation size, vertical phase distribution, and crystallinity remains challenging. Herein, a new L8-BO-derived non-fullerene acceptor, namely BTP- HFCP, featuring a heptafluorocyclopentenyloxy–octyl side chain was developed. When it was integrated as a third component into the D18:L8-BO binary system, BTP-HFCP acts as an effective morphological modulator. Adv. characterizations reveal that the ternary device exhibits a significantly enhanced vertical phase distribution, optimal phase separation and balanced crystallinity, thereby improving chargecollection and reducing recombination. Consequently, the ternary OSC achieves a champion PCE of 19.32%, surpassing the binary OSC. This work demonstrates that heptafluoropentane side-chain engineering of the third component provides a rational molecular design strategy for precise morphology control in high efficiency ternary OSCs.

Organosilicon compounds are widely valuable, making the efficient synthesis of alkenyl silanes an important research goal. A novel catalytic system based on a tridentate anionic ligand and cobalt has been developed for the Markovnikov-selective hydrosilylation of terminal aliphatic alkynes, followed by isomerization of the disubstituted alkenyl silane intermediate, providing efficient access to trisubstituted alkenyl silanes. This system is also highly effective for the Markovnikov hydrosilylation of aryl alkynes. The protocol demonstrates broad functional group tolerance and can be performed on a gram scale. The catalyst achieves a turnover number (TON) of up to 1760 in hydrosilylation reaction. Mechanistic studies suggest that the anionic ligand, upon coordination, forms a dual functional catalyst with cobalt, which is key to enabling this transformation. It is proposed that a cobalt-hydride species selectively catalyzes both the hydrosilylation of terminal alkynes and the subsequent isomerization of the disubstituted alkenyl silane. This work provides an efficient and selective synthetic method using an earth-abundant metal catalyst for alkene synthesis via hydrosilylation and isomerization.

Water microdroplets provide a unique environment that facilitates chemical reactions at the air-water interface. Here, we provide mass spectrometric evidence that several types of fluorinated ethanol increase their acidity and undergo efficient deprotonation at the air–water interface of microdroplets, generating anions that capture CO₂ to form stable fluoroethoxyformate products. While increased fluorine substitution enhances the acidity by stabilizing conjugate bases through electron-withdrawing effect, it simultaneously reduces the nucleophilicity of the bases by delocalizing their negative charges from oxygen atoms. This correlation between acidity of fluorinated ethanols and nucleophilicity of their conjugate bases results in monofluorinated ethanol exhibiting the highest reactivity toward CO₂. Our results elucidate how fluorine substitution modulates anion reactivity and provide a strategy for CO₂ capture in microdroplets where the acidity of various substances could be greatly increased.

Transition-metal catalyzed reductive carbosilylation of alkenes with carbon and silyl electrophiles has gained considerable attention for synthetic chemists recently, because it avoids air- and moisture-sensitive pre-prepared organometallic reagents used. However, current carbon electrophiles are limited to alkyl or aryl bromides. Therefore, developing new synthetic approaches by choosing more easily available carbon electrophiles is still in high demand. Herein, we describe a nickel-catalyzed protocol that enables alkylsilylation of acrylonitrile with chlorosilanes and alkyl carboxylic acids via NHPI esters for the construction of various alkylsilanes, in which abundant and easy-accessible carboxylic acids were employed as the new alkyl electrophile sources, overcoming current limitations. This represents the first example of utilizing carboxylic acid as the alkyl reagent in reductive silylative alkylation of alkenes, thus providing a valuable complement to existing methodologies for the synthesis of a variety of organosilanes with diverse structures. Our approach also showcases broad substrate scope (including primary, secondary and tertiary carboxylic acids), good functional group compatibility (tolerating halides, heterocycles, Boc-protected amine, ester, ketone, terminal and internal alkenes, and terminal alkyne) and offers the capability for post-modification of complex agrochemical and pharmaceuticals. In addition, gram-scale reaction further demonstrates the applicable potential of the developed method. Overall, this protocol not only expands the boundaries of reductive difunctionalization reactions of alkenes but also enriches the synthetic toolbox for alkylsilane compounds preparation.

Global priorities in ocean sustainability and biomedical innovation are accelerating the pursuit of materials that can sustain precise and adaptive sensing in complex aqueous environments. As nations invest heavily in marine technology and digital healthcare, underwater perception and communication are emerging as core capabilities for next-generation intelligent systems. Meeting these demands requires materials that can endure dynamic ion-rich conditions while replicating the softness, adaptability, and responsive-ness of biological tissues. Within this context, conductive hydrogels, as a distinctive class of smart polymers, have emerged as essential building blocks for polymer composites capable of multifunctional sensing across marine and physiological environments. Their unique combination of hydrated ion transport, electronic tunability, and tissue-like mechanics enables seamless coupling between electronic systems and biological or fluidic interfaces. However, conventional hydrogels suffer from intrinsic instability, including excessive swelling and conductive-filler leaching, which compromise both mechanical robustness and signal fidelity. Recent advances in water-resistant hydrogels have overcome these limitations through molecular and structural innovations. Hydrophobic modification, reinforced crosslinking, and hierarchical interpenetrating networks have yielded materials with exceptional anti-swelling stability and long-term conductivity under saline and high-pressure conditions. Moreover, the stabilization of conductive interfaces via covalent anchoring, zwitterionic coordination, and hybrid ion–electron conduction ensures reliable signal transmission in dynamic underwater environments. These advances have enabled durable aquatic sensors for underwater motion tracking, physiological monitoring, and environmental perception. Beyond individual achievements, the field is evolving toward intelligent, integrated systems. The next generation of smart polymer sensors will feature multimodal perception, self-healing, biodegradability, and AI-assisted signal interpretation, enabling autonomous adaptation in complex aquatic environments. Looking forward, the fusion of polymer chemistry, bio-inspired materials design, and data-driven intelligence is expected to reshape underwater electronics into a new paradigm, where soft, sustainable, and perceptive hydrogel-based composites serve as the material backbone of future oceanic and biomedical technologies.

Over the past two decades, the development of underwater-stable conductive hydrogels has been propelled by a series of landmark contributions from pioneering scientists worldwide. These milestones span from fundamental theoretical models to innovative structural designs. The concept of double-network (DN) hydrogels, which dramatically enhanced the mechanical strength and anti-swelling capability of hydrogels, was pioneered in 2003 by Jian Ping Gong and T. Kurokawa at Hokkaido University.^[1] In 2009, Nicholas A. Peppas advanced the theoretical understanding of hydrogel swelling by developing a model based on Flory–Huggins theory.^[2] In 2013, Jian Ping Gong and Tao Lin Sun introduced anti-swelling electrolyte hydrogels through tailored cation-anion interactions.^[3] A systematic strategy for stretchable encapsulation of hydrogels with elastomers was reported in 2018 by Zhigang Suo at Harvard University.^[4] This convenient and versatile strategy achieved excellent anti-swelling capability without compromising the hydrogel's intrinsic conductivity. In the same year, Mingjie Liu developed organogel–hydrogel hybrids with outstanding anti-swelling performance.^[5] In 2019, Jian Ping Gong and Hui Guo pioneered spontaneous phase separation to form core–shell architectures for anti-swelling.^[6] In 2020, Suo's group further addressed interfacial issues, establishing the theoretical framework for hydrogel wet adhesion.^[7] In 2021, Ximin He at the University of California, Los Angeles, achieved tough, anti-swelling hydrogels by synergizing freeze-casting and salting-out techniques.^[8] This strategy allowed for conductivity to be easily imparted by introducing polypyrrole without sacrificing the material's strength and toughness. In 2022, Shu-Hong Yu and Huai-Ping Cong developed electronically conductive composites with remarkable underwater stability.^[9] By combining silver nanowires with a polyacrylamide matrix, they created a highly compressible, fatigue-resistant hydrogel whose continuous conductive network provided excellent conductivity and a stable electrical response even after 1000 compression cycles in water. Most recently, in 2024, Jun Fu employed zwitterions and the Hofmeister effect to realize long-term stability of hydrogels in seawater environments.^[10] The introduction of H₂SO₄ both enhanced anti-swelling properties and provided conductive ions, resulting in an ionic conductivity as high as 4.35 S·m^–1 and a sensing signal that showed no significant degradation after 1000 stretching cycles in seawater. In 2025, Rong Ran and Wei Cui developed a strong, anti-swelling hydrogel using the synergistic effects of dense chain entanglement and phase separation.^[11]

The formation of metal–carbon (M–C) bonds represents a fundamental process in organometallic chemistry. A central question arises: what is the maximum number of M–C bonds that can be formed on a single metal center? Over the past decade, Xia and co-workers have been dedicated to addressing this challenge. They developed a strategy based on chelating metal centers with conjugated carbon chains, which allows for the formation of multiple M–C bonds whose number increases with the length of the carbon chain. A landmark achievement came in 2013 with the first synthesis of metallapentalynes, a new class of metal-bridged fused-ring metallacycles with planar Craig aromaticity. These complexes are formally constructed by chelating a metal center with a seven- atom conjugated carbon ligand via three M–C σ bonds. This breakthrough established a new research area termed “carbolong chemistry”, which focuses on the interactions between transition metals and conjugated carbon ligands. Since then, the Xia group has synthesized a diverse family of carbon-based polydentate chelates involving three to five coplanar M–C σ bonds, including the first metal-centered [15]annulene, collectively known as “carbolong complexes”. Moreover, carbolong motifs have been successfully incorporated into polymer backbones, yielding a new class of materials with numerous M–C bonds, referred to as “polycarbolongs”. Both carbolong complexes and polycarbolongs exhibit not only unique structures but also remarkable properties, showing considerable potential in applications such as catalysis, biomedicine, luminescent materials, and photovoltaics. This review summarizes recent advances in the synthesis and applications of carbolong complexes and polycarbolongs.