A fluorescent probe for detection of Hg²⁺ ions constructed by tetramethyl cucurbit[6]uril and 1,2-bis(4-pyridyl)ethene

• Xiaoqian Chen,
• Naqin Yang,
• Yue Ma,
• Xinan Yang and
• Peihua Ma

Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63

• aminopropyl-1-pyrenebutanamide (PBA) was also constructed to detect Fe3+ and Ag+ ions in aqueous solution [33], which can be used as a potentially useful fluorescent sensor. Pang and co-workers found that the fluorescent probe of cucurbit[8]uril (Q[8]) and squaraine dye (SQ2) has a high selectivity for Hg2

Synthesis of a dihalogenated pyridinyl silicon rhodamine for mitochondrial imaging by a halogen dance rearrangement

• Jessica Matthias,
• Thines Kanagasundaram,
• Klaus Kopka and
• Carsten S. Kramer

Beilstein J. Org. Chem. 2019, 15, 2333–2343, doi:10.3762/bjoc.15.226

• NIR mito tracker® probe. Just like the recently published squaraine variant dye MitoESq-635 [58], our SiR dye 15 offers the option of imaging mitochondria in living cells using STED nanoscopy without the necessity of an additional tagging step. In contrast to MitoESq-635, our SiR dye 15 selectively

Identification of optimal fluorescent probes for G-quadruplex nucleic acids through systematic exploration of mono- and distyryl dye libraries

• Xiao Xie,
• Michela Zuffo,
• Marie-Paule Teulade-Fichou and
• Anton Granzhan

Beilstein J. Org. Chem. 2019, 15, 1872–1889, doi:10.3762/bjoc.15.183

• presence of c-myc) [52] and the NIR-emitting squaraine dye CAS-C1 (Φ of up to 0.74 with parallel G4-DNA) [93]. Applications of these dyes can be multiple. As an example, we proposed herein the implementation of a simple two-dye array to classify G4-DNA structures based on their topology. Applications in

2,3-Dibutoxynaphthalene-based tetralactam macrocycles for recognizing precious metal chloride complexes

• Li-Li Wang,
• Yi-Kuan Tu,
• Huan Yao and
• Wei Jiang

Beilstein J. Org. Chem. 2019, 15, 1460–1467, doi:10.3762/bjoc.15.146

• tetralactam macrocycles [14][15][16]. The Smith group has used tetralactam macrocycles to encapsulate and stabilize deep-red fluorescent squaraine dyes for biomedical applications [17][18][19][20]. By introducing water-soluble groups to tetralactam macrocycles, Davis and co-workers realized selective

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• , 4, and 6), (b) increased hydrogen-bonding-acceptor basicity which is obtained by replacing ester carbonyls with amide carbonyls (compare guest templates 7, 8 and 9), and (c) complementary distance between the two carbonyls (compare template 3 with 16). 3.2. Squaraine, thiosquaraine, croconaine, and

• acene guests Rotaxane template 18 in Scheme 2 is a squaraine dye whose central core has two oxygen atoms that can form hydrogen bonds with the tetralactam NH residues. Squaraine rotaxanes were first prepared by the Smith group in 2005 using the Leigh-type clipping method [44]. As a general trend the

• photophysical property of a squaraine dye is improved when it is encapsulated by tetralactam A, B, or C, but squaraine fluorescence is quenched when the dye is encapsulated by tetralactam E whose structure has extremely electron-rich sidewalls [34]. The moderate flexibility of tetralactam A is one of the

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• nanoparticles with the sensitizer Zn-phthalocyanine and the antineoplastic drug docetaxel. These materials might be applicable for dual cancer therapy [15]. Another self-assembled CD nanocarrier for the photoreactive dye squaraine that is useful for photodynamic therapy is described in this Thematic Series [16

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

• significant potential for photodynamic therapy. Herein we report that squaraines can be immobilized on a self-assembled nanocarrier composed of amphiphilic cyclodextrins to enhance their photochemical activity. To this end, a squaraine was equipped with two adamantane moieties that act as anchors for the

• cyclodextrin vesicle surface. The supramolecular immobilization was monitored by using fluorescence spectroscopy and microscopy and the photochemistry of the squaraine was investigated by using absorption spectroscopy. Keywords: cyclodextrin; host–guest chemistry; photodynamic therapy; self-assembly

• ; squaraine; Introduction Photodynamic therapy (PDT) has become a very attractive alternative to traditional cancer therapies due to its efficiency and selectivity [1][2][3][4]. PDT is based on a photosensitizer (PS), which is delivered to cancerous tissue followed by the irradiation with light of an

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• imaging, ion-pair receptors, rotaxane synthesis, squaraine rotaxanes, and synthtavidin technology. The article concludes with a short perspective of likely future directions in biomedical supramolecular chemistry. Keywords: fluorescence; ion-pair receptors; membrane transport; molecular imaging; rotaxane

• ; squaraine; Review From the land of kangaroos to the home of the Fighting Irish I grew up in Myrtleford, a small town in the foothills of the Australian alpine region (Australia has mountains?). The town population of ≈2,500 has hardly changed in fifty years, and I return there regularly to visit my parents

• was vital for efficient rotaxane formation. The interlocked molecule retained its salt binding ability and association of the ions modulated the rotaxane structural dynamics [33][34]. Squaraine rotaxanes The interests in molecular imaging and rotaxane structures merged in 2005 with the discovery and