Highly luminescent palladium(<scp>ii</scp>) complexes with sub-millisecond blue to green phosphorescent excited states. Photocatalysis and highly efficient PSF-OLEDs

Chow, Pui‐Keong; Cheng, Gang; Tong, Glenna So Ming; Ma, Chensheng; Kwok, Wai Ming; Ang, Wai‐Hung; Chung, Clive Yik‐Sham; Yang, Chen; Wang, Feng; Che, Chi‐Ming

doi:10.1039/c6sc00462h

Cited by 113 publications

(101 citation statements)

References 98 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This assignment and the general observation were in agreement with the fact that the Cu (II) d–d transitions are normally close in energy. Note that the magnetic moment of this complex was 2.8 BM, which falls within the range normally observed for octahedral Cu (II) complexes …”

Section: Resultssupporting

confidence: 83%

“…Its diffuse reflectance spectrum showed three bands at 15 345 (ν 1 ), 16 267 (ν 2 ) and 21 475 cm −1 (ν 3 ), which were assigned to 3 A 2g (F)→ 3 T 2g (F), 3 A 2g (F)→ 3 T 1g (F) and 3 A 2g (F)→ 3 T 1g (P) transitions, respectively. The spectrum of the Mn (II) complex showed three bands at 15554, 17475 and 26877 cm −1 which correspond to 4 T 1g → 6 A 1g , 4 T 2g (G) → 6 A 1g and 4 T 1g (D) → 6 A 1g transitions, respectively . The complex had a magnetic moment value 5.58 BM, which confirmed octahedral geometry around the Mn (II) ion.…”

Section: Resultsmentioning

confidence: 76%

See 1 more Smart Citation

Coordination behaviour, molecular docking, density functional theory calculations and biological activity studies of some transition metal complexes of bis‐Schiff base ligand

Zayed

Hindy

2018

Applied Organom Chemis

View full text Add to dashboard Cite

ions were synthesized from reaction with Schiff base ligand 4,6-bis((E)-(2-(pyridin-2-yl)ethylidene)amino)pyrimidine-2-thiol (HL) derived from the condensation of 4,6-diaminopyrimidine-2-thiol and 2-(pyridin-2-yl)acetaldehyde. Microanalytical data, magnetic susceptibility, infrared and 1 H NMR spectroscopies, mass spectrometry, molar conductance, powder X-ray diffraction and thermal decomposition measurements were used to determine the structure of the prepared complexes. It was found that the coordination between metal ions and bis-Schiff base ligand was in a molar ratio of 1:1, with formula [M (HL)(H 2 O) 2 ] X n (M = Mn (II), Co (II), Ni (II), Cu (II) and Cd (II), n = 2; Fe (III), n = 3). Diffuse reflectance spectra and magnetic susceptibility measurements suggested an octahedral geometry for the complexes. The coordination between bis-Schiff base ligand and metal ions was through NNNN donor sites in a tetradentate manner. After preparation of the complexes, biological studies were conducted using Gram-positive (B. subtilis and S. aureus) andGram-negative (E. coli and P. aeruginosa) organisms. Metal complexes and ligand displayed acceptable microbial activity against both types of bacteria. KEYWORDS bis-Schiff base ligand, in vitro biological activity, spectroscopy, thermal analysis, transition metal complexes

show abstract

Section: Resultssupporting

confidence: 83%

Section: Resultsmentioning

confidence: 76%

Coordination behaviour, molecular docking, density functional theory calculations and biological activity studies of some transition metal complexes of bis‐Schiff base ligand

Zayed

Hindy

2018

Applied Organom Chemis

View full text Add to dashboard Cite

show abstract

“…Such obstacles can be minimized through judicious ligand design. Strong σ‐electron donation from the ligand can raise the energy of the low‐lying d‐d states in palladium species . Pincer‐type ligands can also provide the rigid scaffold needed to minimize structural distortion of the excited state …”

Section: Methodsmentioning

confidence: 99%

One‐Pot Tandem Photoredox and Cross‐Coupling Catalysis with a Single Palladium Carbodicarbene Complex

et al. 2018

View full text Add to dashboard Cite

The combination of conventional transition-metalcatalyzedc oupling (2 e À process) and photoredox catalysis (1 e À process) has emerged as apowerful approachtocatalyze difficult cross-coupling reactions under mild reaction conditions.Reported is apalladium carbodicarbene (CDC) complex that mediates both aS uzuki-Miyaura coupling and photoredox catalysis for C À Nb ond formation upon visible-light irradiation. These two catalytic pathwaysc an be combined to promote both conventional transition-metal-catalyzed coupling and photoredox catalysis to mediate CÀHa rylation under ambient conditions with as ingle catalyst in an efficient one-pot process.Carbodicarbenes (CDCs) are carbones (CL 2 )t hat feature ad icoordinated central carbon atom (C 0 ), bearing two lone pairs of electrons,w ith N-heterocyclic carbenes (NHCs) as ligands (L). [1] Because of the two lone pairs on the central carbon atom, CDCs have been implicated as strong sdonating surrogates complementary to the well-established NHCs.T od ate,t hough catalysis with CDC-supported transition-metals is still in its infancy,e fforts have yielded encouraging results in catalysis. [2][3][4][5] As with their NHC counterparts,t he recurring theme in the reactions promoted by CDC-based species,todate,involves a2e À process.Inthe context of cross-coupling reactions,t his is not only true of NHC/CDC-based species,but of transition-metal catalysts in general (Scheme 1). [6] However,t he conventional transitionmetal-catalyzed cross-coupling methodology based on the 2 e À process,where organometallic catalysts are at the groundstate oxidation level, can be prone to inherent limitations.For example,the formation of C sp 3 À C sp 3 or C sp 3 À C sp 2 bonds,which often requires additional chemical manipulations. [7] Thee merging area of visible-light photoredox chemistry using excited-state organometallics has facilitated significant advancement in organic synthesis via 1 e À processes under benign conditions. [7a,8] Concomitantly,t he seminal works on merging conventional cross-coupling and photoredox catalysis have also led to as pin-off synthetic paradigm (Scheme 1a). Within this regime,photoredox catalysts (e.g.RuorIr species) play as econdary role in the cross-coupling reaction by generating radical intermediates to subdue aspecific high-Scheme 1. Strategies for the combination of catalytic photoredoxa nd transition-metal-based coupling reactions. a) Utilizing two distinct catalysts to promote photoredoxa nd cross-coupling. b) Proposed alternative strategy promoted by asingle pre-catalyst. M, N = metal center;X,Y = leaving groups.

show abstract

“…This straightforward synthetic approach coupled with the potential diversity of π-conjugated derivatives of CˆN ligands to tailor photophysical properties led to intensive development in the field with more than 1000 congeners published today [7][8][9][10][11][12][13][14][15][16][17][18][19]. For Pd(II) salts (e.g., chloride or acetate) the direct cyclometalation of 2-phenylpyridine proceeds already at room temperature [6,14,20]. Not surprisingly, a considerable number of π-conjugated CˆN-derivatives 2 of 13 are reported with interesting photophysical and biomedical properties [20,21].…”

Section: Introductionmentioning

confidence: 99%

“…For Pd(II) salts (e.g., chloride or acetate) the direct cyclometalation of 2-phenylpyridine proceeds already at room temperature [6,14,20]. Not surprisingly, a considerable number of π-conjugated CˆN-derivatives 2 of 13 are reported with interesting photophysical and biomedical properties [20,21]. Moreover, the ease of cyclopalladation resulted in the development of ground-breaking catalytic technologies based on Pd-catalysed directed C−H functionalisation [22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Direct Base-Assisted C‒H Cyclonickelation of 6-Phenyl-2,2′-bipyridine

et al. 2020

View full text Add to dashboard Cite

The organonickel complexes [Ni(Phbpy)X] (X = Br, OAc, CN) were obtained for the first time in a direct base-assisted arene C(sp2)–H cyclometalation reaction from the rather unreactive precursor materials NiX2 and HPhbpy (6-phenyl-2,2′-bipyridine) or from the versatile precursor [Ni(HPhbpy)Br2]2. Different from previously necessary C‒Br oxidative addition at Ni(0), an extended scan of reaction conditions allowed quantitative access to the title compound from Ni(II) on synthetically useful timescales through base-assisted C‒H activation in nonpolar media at elevated temperature. Optimisation of the reaction conditions (various bases, solvents, methods) identified 1:2 mixtures of acetate and carbonate as unrivalled synergetic base pairs in the optimum protocol that holds promise as a readily usable and easily tuneable access to a wide range of direct nickelation products. While for the base-assisted C‒H metalation of the noble metals Ru, Ir, Rh, or Pd, this acetate/carbonate method has been established for a few years, our study represents the leap into the world of the base metals of the 3d series.

show abstract

Highly luminescent palladium(ii) complexes with sub-millisecond blue to green phosphorescent excited states. Photocatalysis and highly efficient PSF-OLEDs

Abstract: Pd(II) complexes with long-lived emissive excited states found applications in photo-catalysis and PSF-OLEDs.

Cited by 113 publications

References 98 publications

Coordination behaviour, molecular docking, density functional theory calculations and biological activity studies of some transition metal complexes of bis‐Schiff base ligand

Coordination behaviour, molecular docking, density functional theory calculations and biological activity studies of some transition metal complexes of bis‐Schiff base ligand

One‐Pot Tandem Photoredox and Cross‐Coupling Catalysis with a Single Palladium Carbodicarbene Complex

Direct Base-Assisted C‒H Cyclonickelation of 6-Phenyl-2,2′-bipyridine

Contact Info

Product

Resources

About