Synthesis, Structural Characterization, and Host–Guest Studies of Aminoquinonato-Bridged Re(I) Supramolecular Rectangles

Aminoquinonato bridged Re­(I)-based metallarectangles have been constructed via an orthogonal bonding approach. Self-assembly of Re₂(CO)₁₀ and aminoquinone ligands in the presence of ditopic linear pyridyl ligands has resulted in the formation of metallarectangles of the general formula [{(CO)₃Re­(μ-η⁴-L)­Re­(CO)₃}₂­(μ-N-L′-N)₂] (<b>1</b>–<b>4</b>), wherein <b>1</b>, L = 2,5-bis­(<i>n</i>-butylamino)-1,4-benzoquinonato (bbbq) and N-L′-N = 4,4′-bipyridine (bpy); <b>2</b>, L = 2,5-bis­(phenethylamino)-1,4-benzoquinonato (bpbq) and N-L′-N = 4,4′-bipyridine; <b>3</b>, L = 2,5-bis­(<i>n</i>-butylamino)-1,4-benzoquinonato (bbbq) and N-L′-N = <i>trans</i>-1,2-bis­(4-pyridyl)­ethylene (bpe) and <b>4</b>, L = 2,5-bis­(phenethylamino)-1,4-benzoquinonato (bpbq) and N-L′-N = <i>trans</i>-1,2-bis­(4-pyridyl)­ethylene (bpe). Metallarectangles <b>1</b>–<b>4</b> have been characterized by elemental analysis, IR, NMR, and UV–vis absorption spectroscopic techniques. The molecular structures of <b>1</b> and <b>4</b> were determined by single-crystal X-ray diffraction methods. The molecular recognition capability of <b>1</b> and <b>3</b> with pyrene and triphenylene has been investigated using UV–vis absorption and emission spectroscopic techniques. The formation of host–guest complex has been further corroborated by the single-crystal X-ray structural evidence of carceplex system (<b>3</b>⊃pyrene)·(DMF)

Synthesis and Spectroscopic and Structural Characterization of Oxamidato-Bridged Rhenium(I) Supramolecular Rectangles with Ester Functionalization

Oxamidato-bridged Re­(I)-based supramolecular rectangles with an ester functionality have been synthesized via an orthogonal bonding approach under solvothermal conditions. Self-assembly of Re₂(CO)₁₀ and oxamide ligands (H₂L1 = <i>N</i>,<i>N</i>′-dibutyloxamide, H₂L2 = <i>N</i>,<i>N</i>′-dioctyloxamide, H₂L3 = <i>N</i>,<i>N</i>′-didodecyloxamide, and H₂L4 = <i>N</i>,<i>N</i>′-dibenzyloxamide) with the pyridyl ligand phenyl-1,4-bis­(isonicotinate) (pbin) has resulted in the formation of metallarectangles of general formula [{(CO)₃Re­(μ-η⁴-L)­Re­(CO)₃}₂(μ-pbin)₂] (<b>1</b>–<b>4</b>), wherein L = <i>N</i>,<i>N</i>′-dibutyloxamidato (<b>1</b>), <i>N</i>,<i>N</i>′-dioctyloxamidato (<b>2</b>), <i>N</i>,<i>N</i>′-didodecyloxamidato (<b>3</b>), <i>N</i>,<i>N</i>′-dibenzyloxamidato (<b>4</b>) and pbin = phenyl-1,4-bis­(isonicotinate). The metallarectangles have been characterized using spectroscopic techniques, and single-crystal X-ray structures have been obtained for <b>1</b> and <b>4</b>. The guest binding ability of <b>2</b> has been investigated with a few aromatic amines and an amino ketone using electronic absorption and fluorescence emission spectroscopy, and the results revealed a strong binding interaction between host–guest species. The luminescence properties of <b>2</b> and <b>3</b> have been tuned using organic–aqueous solvent mixtures

Self-assembly of Thiolato-Bridged Manganese(I)-Based Metallarectangles: One-pot Synthesis and Structural Characterization

A new series of thiolato-bridged manganese­(I)-based supramolecular rectangles have been achieved by three-precursor self-assembly of Mn₂(CO)₁₀, diaryl disulfides (RSSR), and linear ditopic azine ligands (L) [L = pyrazine (pz), 4,4′-bipyridine (bpy), and <i>trans</i>-1,2-bis­(4-pyridyl)­ethylene (bpe)] using a one-pot synthetic strategy. Oxidative addition of RSSR (diphenyl disulfide and <i>p</i>-tolyl disulfide) to manganese decacarbonyl in the presence of rigid bidentate ligands (L) afforded metallarectangles of the general formula [{(CO)₃Mn­(μ-SR)₂Mn­(CO)₃}₂(μ-L)₂] (<b>1</b>–<b>6</b>). Compounds <b>1</b>–<b>6</b> were characterized using elemental analyses and NMR, IR, and UV–vis absorption spectroscopic techniques. The molecular structures of metallarectangles <b>1</b>, <b>3</b>, and <b>5</b> were elucidated by single-crystal X-ray diffraction methods. The guest binding ability of <b>3</b> and <b>5</b> has been investigated with two aromatic guests using electronic absorption and fluorescence emission spectroscopy, and the results revealed a strong binding interaction between host–guest species

Self-Assembly of Manganese(I)-Based Molecular Squares: Synthesis and Spectroscopic and Structural Characterization

Syntheses of manganese­(I)-based molecular squares have been accomplished in facile one-pot reaction conditions at room temperature. Self-assembly of eight components has resulted in the formation of M₄L₄-type metallacyclophanes [Mn­(CO)₃Br­(μ-L)]₄ (<b>1</b>–<b>3</b>) using pentacarbonylbromomanganese as metal precursor and rigid azine ligands such as pyrazine, 4,4′-bipyridine, and <i>trans</i>-1,2-bis­(4-pyridyl)­ethylene, respectively, as bridging ligands. The metallacyclophanes have been characterized on the basis of IR, NMR, and UV–vis spectroscopic techniques and single-crystal X-ray diffraction methods

Multicomponent Self-Assembly of Thiolato- and Selenato-Bridged Ester-Functionalized Rhenium(I)-Based Trigonal Metallaprisms: Synthesis and Structural Characterization

Multicomponent self-assembly of Re₂(CO)₁₀, diaryl dichalcogenide ligands (REER), and phenyl-1,3,5-tris­(isonicotinate) (ptin) under solvothermal conditions has resulted in the formation of chalcogen-bridged trigonal metallaprisms of the general formula [{(CO)₃Re­(μ-ER)₂Re­(CO)₃}₃(μ₃-ptin)₂] (<b>1</b>–<b>5</b>), wherein E = S, Se and R = phenyl, <i>p</i>-tolyl, benzyl. Oxidative addition of diaryl disulfide/diaryl diselenide to Re₂(CO)₁₀ with the ester-functionalized tritopic linker ptin has yielded trigonal metallaprisms <b>1</b>–<b>5</b> under facile reaction conditions. The metallaprisms <b>1</b>–<b>5</b> have been characterized using elemental analysis and IR, UV–vis, and NMR spectroscopic techniques. Single-crystal X-ray structures have been obtained for <b>3</b> and <b>4</b>. The structural features and chirality of metallaprisms <b>3</b> and <b>4</b> in the solid state have been highlighted

Amide-Functionalized Chalcogen-Bridged Flexible Tetranuclear Rhenacycles: Synthesis, Characterization, Solvent Effect on the Structure, and Guest Binding

The synthesis of flexible rhenium­(I)-based amide-functionalized chalcogen-bridged tetranuclear metallacycles of general formula [{(CO)₃Re­(μ-ER)₂Re­(CO)₃}₂(μ-L)₂] (<b>1–8</b>) was achieved by treating rhenium carbonyl with dialkyl/diaryl chalcogenide (RE–ER; E = S and Se) in the presence of ditopic flexible or semiflexible pyridyl ligand with amide functionality (L = <i>N</i>,<i>N</i>′-bis­(4-pyridylcarboxamide)-1,2-ethane (bpce) and <i>N</i>,<i>N</i>′-bis­(4-(4-pyridylcarboxamide)­phenyl)­methane (bpcpm)). Compounds <b>1–8</b> were formed by multicomponent self-assembly under one-pot reaction conditions via oxidative addition of dialkyl/diaryl chalcogenide to rhenium carbonyl with pyridyl ligands. The resultant metallacyclophanes were characterized using elemental analyses, infrared, ultraviolet–visible, and NMR spectroscopic techniques. Metallacyclophanes <b>1–3</b> and <b>7</b> were structurally characterized by single-crystal X-ray diffraction methods. The solvent-induced structural change of flexible tetranuclear metallacyclophane <b>2</b> was demonstrated by crystallizing <b>2</b> in dichloroethane and dimethylformamide. Molecular recognition capabilities of <b>2</b> and <b>7</b> were studied with few aromatic compounds containing ethereal linkages

Amide-Functionalized Chalcogen-Bridged Flexible Tetranuclear Rhenacycles: Synthesis, Characterization, Solvent Effect on the Structure, and Guest Binding

The synthesis of flexible rhenium­(I)-based amide-functionalized chalcogen-bridged tetranuclear metallacycles of general formula [{(CO)₃Re­(μ-ER)₂Re­(CO)₃}₂(μ-L)₂] (<b>1–8</b>) was achieved by treating rhenium carbonyl with dialkyl/diaryl chalcogenide (RE–ER; E = S and Se) in the presence of ditopic flexible or semiflexible pyridyl ligand with amide functionality (L = <i>N</i>,<i>N</i>′-bis­(4-pyridylcarboxamide)-1,2-ethane (bpce) and <i>N</i>,<i>N</i>′-bis­(4-(4-pyridylcarboxamide)­phenyl)­methane (bpcpm)). Compounds <b>1–8</b> were formed by multicomponent self-assembly under one-pot reaction conditions via oxidative addition of dialkyl/diaryl chalcogenide to rhenium carbonyl with pyridyl ligands. The resultant metallacyclophanes were characterized using elemental analyses, infrared, ultraviolet–visible, and NMR spectroscopic techniques. Metallacyclophanes <b>1–3</b> and <b>7</b> were structurally characterized by single-crystal X-ray diffraction methods. The solvent-induced structural change of flexible tetranuclear metallacyclophane <b>2</b> was demonstrated by crystallizing <b>2</b> in dichloroethane and dimethylformamide. Molecular recognition capabilities of <b>2</b> and <b>7</b> were studied with few aromatic compounds containing ethereal linkages

One-Pot Synthesis of Ruthenium Metallacycles via Oxidative Addition of Diaryldichalcogen and Halogen across a Ru–Ru Bond

Oxidative addition of diaryldichalcogen ligands (REER) to ruthenium carbonyl (Ru₃(CO)₁₂) followed by the addition of halogen (X₂) afforded chalcogen-bridged Ru­(II)-based metallacycles of general formula [X­(CO)₃Ru­(μ-ER)₂Ru­(CO)₃X] (<b>1</b>–<b>10</b>), where E = S, Se, and Te; R = phenyl, tolyl, and benzyl; and X = Br and I. Compounds <b>1</b>–<b>10</b> were characterized using IR, UV–vis, and NMR spectroscopic techniques. Molecular structures of the metallacycles have been elucidated by single-crystal X-ray diffraction methods that confirm the dimeric nature of metallacycles, wherein the two Ru­(CO)₃X moieties are held together by the bridging aryl chalcogenide ligands

One-Pot Synthesis of Ruthenium Metallacycles via Oxidative Addition of Diaryldichalcogen and Halogen across a Ru–Ru Bond

Oxidative addition of diaryldichalcogen ligands (REER) to ruthenium carbonyl (Ru₃(CO)₁₂) followed by the addition of halogen (X₂) afforded chalcogen-bridged Ru­(II)-based metallacycles of general formula [X­(CO)₃Ru­(μ-ER)₂Ru­(CO)₃X] (<b>1</b>–<b>10</b>), where E = S, Se, and Te; R = phenyl, tolyl, and benzyl; and X = Br and I. Compounds <b>1</b>–<b>10</b> were characterized using IR, UV–vis, and NMR spectroscopic techniques. Molecular structures of the metallacycles have been elucidated by single-crystal X-ray diffraction methods that confirm the dimeric nature of metallacycles, wherein the two Ru­(CO)₃X moieties are held together by the bridging aryl chalcogenide ligands

Self-Assembly of Selenium-Bridged Rhenium(I)-Based Metalla Rectangles: Synthesis, Characterization, and Molecular Recognition Studies

Self-assembly of the selenium-bridged novel metallacyclophanes [{(CO)₃Re­(μ-SeR)₂Re­(CO)₃}₂(μ-L)₂] (<b>1</b>–<b>3</b>) has been accomplished by treating diaryl diselenide with low-valent transition-metal carbonyl and rigid bidentate azine ligands under one-pot reaction conditions. The oxidative addition of diphenyl/dibenzyl diselenides to Re₂(CO)₁₀ with 4,4′-bipyridine, <i>trans</i>-1,2-bis­(4-pyridyl)­ethylene, and 1,4-bis­[2-(4-pyridyl)­ethenyl]­benzene afforded tetranuclear metallacyclophanes. These compounds have been characterized by elemental analysis and IR, NMR, and UV–vis absorption spectroscopic techniques. The molecular structures of metallacylophanes <b>1a</b>,<b>b</b> and <b>2</b> were determined by single-crystal X-ray diffraction methods, and the crystal structures showed that two selenium-bridged dirhenium metallacycles were linked by two bipyridyl spacers and attained a framework of molecular rectangles. In addition, the molecular recognition capabilities of the molecular rectangles <b>1a</b>,<b>b</b> and <b>2</b> with aromatic compounds such as pyrene and triphenylene have been investigated by studying their binding properties, using UV–visible absorption and fluorescence emission spectrophotometric methods. The nature of the binding interactions were further supported by single-crystal X-ray diffraction methods, and the crystal structures of <b>1</b><b>b</b>·(pyrene) and <b>1</b><b>b</b>·(triphenylene) revealed that CH···π interactions are mainly responsible for the binding of <b>1b</b> with pyrene and triphenylene