A new class of solvatochromic material: Geometrically unsaturated Ni (II) complexes

Selvakumar, P. Mosae; Nadella, Sandeep; Fröhlich, Roland; Albrecht, Markus; Subramanian, P.

doi:10.1016/j.dyepig.2012.05.008

Cited by 12 publications

(7 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the absorption spectra (Figure ), the three well-resolved metal-centered transitions for Ni- 1 , Ni- 2 , Ni- 3 at 1364, 1423, and 1390 and 1130, 1140, and 1154 nm, respectively, correspond to 3 A 2g → 3 T 2g , and the third electronic transitions at 872, 872, and 868 nm correspond to 3 A 2g → 3 T 1g . These transitions match the distorted octahedral geometry of related Ni(II) complexes . The absorption spectra for the corresponding Zn(II) helicates show a similar pattern; the ligand-centered transitions occurred at 290 nm.…”

Section: Results and Discussionsupporting

confidence: 54%

“…These transitions match the distorted octahedral geometry of related Ni(II) complexes. 27 The absorption spectra for the corresponding Zn(II) helicates show a similar pattern; the ligand-centered transitions occurred at 290 nm. The transition at 365 nm represents σ → π*, corresponding to ketonic oxygen to metal, while the metal-centered region is flat.…”

Section: ■ Results and Discussionmentioning

confidence: 83%

See 1 more Smart Citation

Catalytic Conversion of Carbon Dioxide Using Binuclear Double-Stranded Helicates: Cyclic Carbonate from Epoxides and Diol

et al. 2020

View full text Add to dashboard Cite

The construction of sophisticated molecular architectures from chemical subunits requires careful selection of the spacers, precise synthetic strategies, and substantial efforts. Here, we report a series of binuclear double-stranded helicates synthesized from different combinations of pyridyl hydrazone-based multidentate ligands (H2 1, H2 2, H2 3) by increasing the methylene spacer and transition metals (Co, Ni, and Zn). The ligands H2 1 (N′1,N′3-bis((E)-pyridin-2-ylmethylene)malonohydrazide), H2 2 (N′1,N′4-bis((E)-pyridin-2-ylmethylene)succinohydrazide), and H2 3 (N′1,N′5-bis((E)-pyridin-2-ylmethylene)glutarohydrazide) and their respective complexes with Co, Ni, and Zn were obtained. Single-crystal X-ray diffraction studies of these binuclear metallohelicates confirm the double-stranded helical structure of the complexes derived from H2 2. The set of helicates Co-1, Co-2, and Co-3; Ni-1, Ni-2, and Ni-3; and Zn-1, Zn-2, and Zn-3 were investigated for its catalytic activity in the cyclic carbonate formation reaction. Intriguingly, among the synthesized catalyst, Co-1 was found to be better in terms of conversions with the calculated TOF (turnover frequency) of 128/h. The catalytic performance was significantly improved by adding 0.2 mmol of tetrabutylammonium bromide by achieving 76% conversion in 30 min, with the observed TOF of 15,934 h–1/molecule and 7967 h–1/Co center. The results obtained herein show that the double-stranded helicates are effective catalysts for converting both terminal and non-terminal epoxides into their corresponding cyclic carbonates. The striking feature of this catalytic protocol lies in demonstrating the catalytic activity for the conversion of diol to cyclic carbonate, and the detailed kinetic experiments tempted us to propose a tentative reaction mechanism for this conversion.

show abstract

Section: Results and Discussionsupporting

confidence: 54%

Section: ■ Results and Discussionmentioning

confidence: 83%

Catalytic Conversion of Carbon Dioxide Using Binuclear Double-Stranded Helicates: Cyclic Carbonate from Epoxides and Diol

et al. 2020

View full text Add to dashboard Cite

show abstract

“…An additional band attributable to charge transfer transition occurred at 406 nm, and the d‐d band at 620 nm revealed a pentacoordinate geometry of Cu(II) centre (S11). Similarly, the respective NiL R , NiL S complexes ( Figure c) behaving little different in their electronic spectra, the bands correspond to d‐d transition at 524 and 909 nm were observed . In the case of zinc complexes, the electronic spectra matching with the ligand, the respective 1 H NMR spectra recorded for ligands shows a sharp singlet at 8.40 ppm corresponds to azomethine and the minor shift to 8.45 δ in their respective complexes confirms the coordination.…”

Section: Metal Complexesmentioning

confidence: 99%

Enantio- and Diastereoselective Synthesis of β-Nitroalcohol via Henry Reaction Catalyzed by Cu(II), Ni(II), Zn(II) Complexes of Chiral BINIM Ligands

2016

View full text Add to dashboard Cite

Enantiopure Cu(II), Ni(II) and Zn(II) chiral complexes CuLR, CuLS, NiLR, NiLS, ZnLR and ZnLS were synthesised by using ligands LR and LS, which were derived from the (R)‐(+)‐1,1’‐Binaphthyl‐2,2′‐diamine or (S)‐(−)‐1,1’‐Binaphthyl‐2,2’‐diamine with pyridine‐2‐aldehyde. These six complexes are characterised and applied as a catalyst for asymmetric nitroaldol reaction. The enantiopure chiral ligand upon complexation transfers its chirality from ligand to metal and generate “Δ or Λ” chirality at the metal centre. All these associated chiral responses were monitored using circular dichroism. Ensuring the enantiopure nature of the complexes they have been demonstrated as an efficient enantioselective catalyst for nitroaldol reaction. Further, this asymmetric catalytic study has been extended to various nitroalkanes such as nitromethane, nitroethane and nitropropane with substituted benzaldehydes leading to the synthesis of various diastereoselective β‐nitroalcohols.

show abstract

“…Various organic12345678910, organometallic1112, metal organic framework1314 and hybrid1516 materials have been investigated to determine their solvatochromic properties in diverse solvents. Conventional colorimetric sensors, however, inevitably display changes in absorption and emission peaks that are in indiscriminant in their response to organic solvents.…”

mentioning

confidence: 99%

A protective layer approach to solvatochromic sensors

et al. 2013

View full text Add to dashboard Cite

As they have been designed to undergo colorimetric changes that are dependent on the polarity of solvents, the majority of conventional solvatochromic molecule based sensor systems inevitably display broad overlaps in their absorption and emission bands. As a result, colorimetric differentiation of solvents of similar polarity has been extremely difficult. Here we present a tailor-made colorimetric and fluorescence turn-on type solvatochromic sensor that enables facile identification of a specific solvent. The sensor system displays a colorimetric transition only when a thin protective layer, which protects the solvatochromic materials, is destroyed or disrupted by a specific solvent. The versatility of the strategy is demonstrated by designing a sensor that differentiates chloroform and dichloromethane colorimetrically and one that performs sequence selective colorimetric sensing. In addition, the approach is employed to construct a solvatochromic molecular AND logic gate. The new strategy could open new avenues for the development of novel solvatochromic sensors.

show abstract

A new class of solvatochromic material: Geometrically unsaturated Ni (II) complexes

Cited by 12 publications

References 56 publications

Catalytic Conversion of Carbon Dioxide Using Binuclear Double-Stranded Helicates: Cyclic Carbonate from Epoxides and Diol

Catalytic Conversion of Carbon Dioxide Using Binuclear Double-Stranded Helicates: Cyclic Carbonate from Epoxides and Diol

Enantio- and Diastereoselective Synthesis of β-Nitroalcohol via Henry Reaction Catalyzed by Cu(II), Ni(II), Zn(II) Complexes of Chiral BINIM Ligands

A protective layer approach to solvatochromic sensors

Contact Info

Product

Resources

About