CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• hexagonal columnar phases in their pure states and can form organogels in 1,4-dioxane with an unusual flower-like sphere morphology. Ol'shevskaya et al. [64] recently established a CuAAC-based synthesis of a novel series of meso-triazoloporphyrin-carborane conjugates, as shown in Scheme 33. First, the

Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system

• David Liese,
• Hans Henning Wenk,
• Xin Lu,
• Jochen Kleinen and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232

• reverse wormlike micelles, whereas most surfactants need to be purified, e.g., by recrystallization [54]. Also, the prototype of reverse micelles, organogels by lecithin, has high expectations towards the purity of the molecules [19]. Experimental Differential scanning calorimetry DSC data were obtained

Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

• Juan V. Alegre-Requena,
• Marleen Häring,
• Isaac G. Sonsona,
• Alex Abramov,
• Eugenia Marqués-López,
• Raquel P. Herrera and
• David Díaz Díaz

Beilstein J. Org. Chem. 2018, 14, 2065–2073, doi:10.3762/bjoc.14.180

• properties of the gels obtained with these compounds. In general, compound 2 formed gels in more solvents, at lower concentration and faster than compound 1. In this work, and based on our previous experience with organogels based on squaramides [21], we decided to prepare and study an analogue of N-stearoyl

• of organogels In general, all gels displayed relatively low gel-to-sol transition temperatures (Tgel) ranging from 26 to 52 °C (±2, Table 1). A comparative study made with a population of six gels showed that the Tgel of the gels made of 3 were in general ca. 10 °C lower than those obtained using

• organogels were conducted by field emission scanning electron microscopy (FESEM) of the corresponding xerogels obtained by the freeze-drying method (Figure 4). The remarkable influence of the solvents on the morphologies was evident among different samples. For instance, the specimens prepared in ethyl

A self-assembled photoresponsive gel consisting of chiral nanofibers

• Lei Zou,
• Dan Han,
• Zhiyi Yuan,
• Dongdong Chang and
• Xiang Ma

Beilstein J. Org. Chem. 2018, 14, 1994–2001, doi:10.3762/bjoc.14.174

• structure, and the nanostructures of the assembled compound 3 can be adjusted by both solvent and light. The formation of organogels in various solvents was conducted to test the gelation ability of compound 3. The gel was fabricated by melting compound 3 in solution by heating for about 20 min, followed by

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• LMWGs can immobilize organic solvents (forming organogels) and water or aqueous solvents (forming hydrogels) under different experimental conditions. Gels, so formed are supramolecular in nature as they result from self-assembly of the gelator molecules through secondary interactions like H-bonding, π

• summarized in Table 1. Three of the compounds (TPM-G4, TPM-G5, TPM-G12) formed organogels in polar solvents like dimethylsulfoxide (DMSO), propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, diethylene glycol, and triethylene glycol. TPM-G5 (trityl derivative of 1-hexadecanol) formed an organogel in DMSO while

• loss of the entrapped solvent from the gels. TPM-G5 also formed a strong gel in DMSO which is stable at room temperature for a long time (≈2 weeks). In contrast, organogels formed from TPM-G4 in diethylene glycol and triethylene glycol were weak and not stable at prolonged storage (≈2 days). This is

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

• Yuchun Ren,
• Bin Wang and
• Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

• . Different solvents caused a sharp difference between these morphologies of the xerogels. The FTIR spectroscopy It should be emphasized that the organogels achieved through strength and directionality of hydrogen bonding. Further information about the intermolecular interactions of these gels was obtained

• shifted to 2933 and 2859 cm−1. The above mentioned FTIR spectral changes demonstrated sufficiently that van der Waals interaction between the alkyl chains plays an important role in the self-assembly process of organogels. The XRD studies To reveal the detailed changes in gel molecular of M6, XRD analyses

Synthesis and characterization of pH responsive D-glucosamine based molecular gelators

• Navneet Goyal,
• Hari P. R. Mangunuru,
• Bargav Parikh,
• Sonu Shrestha and
• Guijun Wang

Beilstein J. Org. Chem. 2014, 10, 3111–3121, doi:10.3762/bjoc.10.328

• be effective LMWGs, including derivatives from amino acids, carbohydrates, and cholesterols derivatives [8][9][10][11][12][13][14][15][16]. The reversible organogels and hydrogels have been explored for many applications including drug delivery, protein binding and separation, tissue engineering, and

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• was significantly less pronounced than those seen in water-in-oil systems [94]. AOT surfactant organogels have also been induced in isooctane through the addition of trace levels of para-substituted phenols (p-ethylphenol and p-methylphenol, Figure 8), with reports of vast viscosity enhancements up to

Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

• Simon Rondeau-Gagné,
• Jules Roméo Néabo,
• Maxime Daigle,
• Katy Cantin and
• Jean-François Morin

Beilstein J. Org. Chem. 2014, 10, 1613–1619, doi:10.3762/bjoc.10.167

• the xerogel state to form polydiacetylenes (PDAs), leading to a significant enhancement of the polymerization yields. The organogels and the PDAs were characterized using Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Keywords: carbon nanomaterials; organogels

• π-conjugated monomers capable of hydrogen bonding to create nanowires [21][22][23], nanoparticles [24][25][26][27], nanotubes [28][29][30][31] and two-dimensional layered materials [32] from organogels. The key to success was to obtain a good balance between solubility and gelation properties

• groups lead to a significant decrease of solubility, even in hot solvents, limiting the formation of organogels. In order to investigate the crystallization temperature of solvents within the gel and to compare the influence of the 2-hydroxyethoxy side chains on the thermal stability of the gel, two gel

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• properties. UV–vis, fluorescence, mass spectrometric as well as variable-temperature 1H NMR experiments on these gels suggest that the CT interaction is one of the major driving forces for the formation of these organogels. Keywords: charge transfer; glycyrrhetinic acid; organogel; self-assembly

• –vis region [25]. CT interactions have been employed to induce the supramolecular interactions between donors and acceptors, and lead to the formation of two-component organogels [26][27][28][29][30]. 18β-Glycyrrhetinic acid (GA, 1), a natural pentacyclic triterpenoid obtained from medicinal plants in

• powerful building blocks for materials development due to their unique rigid molecular structures [35][36][37][38][39][40][41]. In our previous work, we have already reported the synthesis of organogels based on triterpenoid moieties. For example, we designed and studied the one-component organogelation

Self-assembly of 2,3-dihydroxycholestane steroids into supramolecular organogels as a soft template for the in-situ generation of silicate nanomaterials

• Valeria C. Edelsztein,
• Andrea S. Mac Cormack,
• Matías Ciarlantini and
• Pablo H. Di Chenna

Beilstein J. Org. Chem. 2013, 9, 1826–1836, doi:10.3762/bjoc.9.213

• key to the directed design of new organogels. We report herein the organogelating property of four stereoisomers of the simple steroid 2,3-dihydroxycholestane. Only the isomer with the trans-diaxial hydroxy groups had the ability to gelate a broad variety of liquids and, thus, to be a super

• a self-supporting gel. There are several types of cholesterol-based LMOGs grafted on hydrophilic heads such as saccharides, chromophores, ligands, peptides, etc. The first study on rational syntheses of cholesterol derived organogels was made by Weiss et al. [23] on a family of molecules containing

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• -bonding domain has been incorporated as the electron-deficient moiety in a “push–pull” p-type molecule 2 for organic solar cells. Self-association of this domain could be monitored by 1H NMR, and at higher concentrations the compound was found to form nanostructures and organogels. In bulk heterojunction

Protonation and deprotonation induced organo/hydrogelation: Bile acid derived gelators containing a basic side chain

• Uday Maitra and
• Arkajyoti Chakrabarty

Beilstein J. Org. Chem. 2011, 7, 304–309, doi:10.3762/bjoc.7.40

• -assembled structures form mainly due to weak non-covalent interactions such as hydrogen-bonding, van der Waals forces, π–π interactions, charge-transfer interactions etc. in organogels, whereas, in aqueous gels, the major driving force for aggregation is hydrophobic interaction [2]. A number of

Amphiphilic dendritic peptides: Synthesis and behavior as an organogelator and liquid crystal

• Baoxiang Gao,
• Hongxia Li,
• Defang Xia,
• Sufang Sun and
• Xinwu Ba

Beilstein J. Org. Chem. 2011, 7, 198–203, doi:10.3762/bjoc.7.26

• ; liquid crystal; organogels; Introduction Peptide self-assembly has drawn a significant attention due to potential applications, especially in the fields of biomedicine and bionanotechnology [1][2][3]. Programmed self-assembly of peptides into highly ordered nanostructures creates biomaterials that

• oligopeptides can act as useful building blocks for chiral supramolecular liquid crystals [15][16]. Herein, we present the synthesis of amphiphilic dendritic peptides (ADPs) composed of an aspartic acid core and an aliphatic periphery, and their self-assembly which leads not only to organogels but also to

• organogels assembled from G3 formed thin fibres that underwent further aggregation to form fibre bundles. These fibre bundles constitute a highly developed entangled network. Figure 2 shows the XRD scan of organogelator G3 and liquid crystal G3. Being different from the liquid crystal, the XRD of

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• interest in the recent past due to their potential applications as active components in a variety of organic electronic devices [2]. Organogels are a special class of self-assembled materials in which small building blocks generate fibrous structures due to intermolecular non-covalent interactions, and

• these elongated fibres form interpenetrating network in which the solvent molecules are trapped [3][4]. Organogels based on various π-systems such as oligophenylenevinylenes [5] and thienylenevinylenes [6] oligophenyleneethylenes [7], phthalocyanines [8], porphyrins [9], naphthalene and perylene

• bisimides [10][11][12], acenes [13][14] and merocyanines [15][16] have been studied in recent years. Self-assembly of various oligothiophene derivatives have been extensively investigated on account of their semiconducting and optoelectronic properties [17]. Feringa and co-workers reported organogels based

Expanding the gelation properties of valine-based 3,5-diaminobenzoate organogelators with N-alkylurea functionalities

• Hak-Fun Chow and
• Chin-Ho Cheng

Beilstein J. Org. Chem. 2010, 6, 1015–1021, doi:10.3762/bjoc.6.114

• , the cumulative hydrophobic interaction between organogelator molecules with longer aliphatic chains must be stronger than that of the shorter ones, and this factor should contribute to the higher thermal stability of the longer chain organogels. In addition, the presence of the long aliphatic chain

Differences between β-Ala and Gly-Gly in the design of amino acids-based hydrogels

• Andreea Pasc,
• Firmin Obounou Akong,
• Sedat Cosgun and
• Christine Gérardin

Beilstein J. Org. Chem. 2010, 6, 973–977, doi:10.3762/bjoc.6.109

• organogels and hydrogels of low molecular weight gelators (LMWG), establishing the relationship between the molecular structure and the gelation mechanism is still a challenge. In this paper our interest focuses on the consequences of slight molecular modifications on the self-assembling behaviour of β-Ala

Towards racemizable chiral organogelators

• Jian Bin Lin,
• Debarshi Dasgupta,
• Seda Cantekin and
• Albertus P. H. J. Schenning

Beilstein J. Org. Chem. 2010, 6, 960–965, doi:10.3762/bjoc.6.107

• organogelator has been synthesized that can be racemized and self-assembled in apolar solvents whilst at higher concentrations organogels are formed. Field emission scanning and transmission electron microscopy revealed the formation of bundle fibrils that are able to gelate the solvent. 1H NMR studies showed

• ; organogels; racemization; self-assembly; Introduction Gelation represents a macroscopic manifestation of self-assembled molecules. Impressive supramolecular architectures have been reported in which the self-assembled molecules immobilize solvent to produce a gel phase. Carefully designed self complementary

• building blocks with co-added organizational information can make these gels responsive. In recent years, much effort has been devoted to the design and characterization of chiral self-assembled fibrillar networks that form organogels [1][2]. In such systems the chirality within a molecular building block

Chiral gels derived from secondary ammonium salts of (1R,3S)-(+)-camphoric acid

• Tapas Kumar Adalder,
• N. N. Adarsh,
• Ravish Sankolli and
• Parthasarathi Dastidar

Beilstein J. Org. Chem. 2010, 6, 848–858, doi:10.3762/bjoc.6.100

• (PG) with bromobenzene, chlorobenzene, 1,2-dichlorobenzene; a gel is called PG when the top layer of the solution becomes gel-like entrapping the flowing liquid underneath [47]. DHADC 5 gave a weak gel with nitrobenzene and 1,4 dioxane. Representative photomicrographs of the organogels are depicted in

• @ccdc.cam.ac.uk). Photomicrographs of the organogels (from left to right: nitrobenzene gel of DBUAMC 3; 1,2-dichlorobenzene gel of DBAMC 6; chlorobenzene gel of DBAMC 6; bromobenzene gel of DBAMC 6). DSC of a 4.0 wt % 1,2-dichlorobenzene gel of DBAMC 6. Left – Tgel vs [gelator] plot; right – semilog plot of mole

Organic gelators and hydrogelators

• Jean-Pierre Desvergne

Beilstein J. Org. Chem. 2010, 6, 846–847, doi:10.3762/bjoc.6.99

• an understanding of the mechanism of gelation. It is also important to develop future green gelators for eco-compatible applications. This thematic series on organogels and hydrogels will address these various points with a particular emphasis on the molecular requirements on the gelling ability, the