Cyclometallated, bis-terdentate iridium complexes as linearly expandable cores for the construction of multimetallic assemblies

Whittle, Victoria L.; Williams, J. A. Gareth

doi:10.1039/b821161b

Cited by 66 publications

(30 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, Whittle and Williams, Haga and co‐workers, De Cola and co‐workers, and Esteruelas and co‐workers have independently conducted studies on emitters bearing two tridentate chelates; namely bis‐tridentate metal complexes. This class of molecular designs is expected to be more robust and should be of higher efficiency attributed to the concomitant higher rigidity versus the traditional design bearing three bidentate chelates .…”

Section: Methodsmentioning

confidence: 99%

Bis‐Tridentate Ir(III) Metal Phosphors for Efficient Deep‐Blue Organic Light‐Emitting Diodes

et al. 2017

View full text Add to dashboard Cite

which the developments still lag behind the green and red counterparts due to the intrinsically wider energy gaps. [2] Efficient blue-emitters are expected to reduce power consumption and improve color gamut; therefore, they have emerged as one paradigm of the full-color OLED displays and solid-state lighting. [3] Among the various known blue phosphors, the sky-blue emitter FIrpic is considered to be the archetypal design; hence, its modulation is at the forefront of modern research in OLEDs. [4] OLEDs made with FIrpic typically have Commission Internationale de l'Eclairage (CIE (x,y) ) coordinates of (0.17, 0.34) which is far from the National Television Standards Committee pure blue values of (0.14, 0.08). Progress with blue phosphors is further complicated by other issues, such as chemical and physical stabilities, emission quantum yield, and relative radiative lifetime. Moreover, almost all reports of decent blue phosphors were focused on the so-called tris-bidentate architectures, i.e., with either three bidentate cyclometalates of higher ligand-centered ππ* energy gap or two of these cyclometalate plus a third bidentate ancillary. [5] However, these complexes suffer from possible chelate dissociation upon excitation, giving inferior device performances and longevity. [6] Recently, Whittle and Williams, [7] Haga and co-workers, [8] De Cola and co-workers, [9] and Esteruelas and co-workers [10] have independently conducted studies on emitters bearing two tridentate chelates; namely bis-tridentate metal complexes. This class of molecular designs is expected to be more robust and should be of higher efficiency attributed to the concomitant higher rigidity versus the traditional design bearing three bidentate chelates. [11] Despite the obvious advantages, these associated studies were greatly hampered by the lack of systematic syntheses and poor performances on OLEDs. These difficulties were recently solved by proper selection of chelates to give the charge-neutral architecture [12] and the installment of a higher field strength coordination unit. [13] One known bis-tridentate metal complex is the sky-blue Ir(III) phosphor [Ir(mimf)(pzpyph F )] (SB = "sky-blue"), [14] where the tridentate 6-pyrazolyl-2-phenylpyridine (pzpyph F ) and pincer dicarbene chelate (mimf) act as the chromophoric and ancillary chelates, respectively (Scheme 1). These ligands control the emission color and give the greater ligand field strength needed for the efficient phosphors. [15] Hence, the OLED derived from SB gave maximum external quantum efficiency (max. EQE) of 27% and EQE of 24% at the practical Emissive Ir(III) metal complexes possessing two tridentate chelates (bis-tridentate) are known to be more robust compared to those with three bidentate chelates (tris-bidentate). Here, the deep-blue-emitting, bis-tridentate Ir(III) metal phosphors bearing both the dicarbene pincer ancillary such as 2,6-diimidazolylidene benzene and the 6-pyrazolyl-2-phenoxylpyridine chromophoric chelate are synthesized. A deep-blue organic light-em...

show abstract

Section: Methodsmentioning

confidence: 99%

Bis‐Tridentate Ir(III) Metal Phosphors for Efficient Deep‐Blue Organic Light‐Emitting Diodes

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In this chapter, emphasis will be placed in describing the changes of the luminescent properties of the guest iridium complexes due to their physical and optoelectronic interactions with the host materials. It is worth noting that a number of studies involving luminescent Ir (III) complexes covalently assembled within multinuclear dyads, triads and arrays, [49][50][51] or covalently linked onto polymeric structures [52][53][54] have been reported. As these systems have been extensively described elsewhere, they are not included within the present review.…”

Section: Introductionmentioning

confidence: 99%

Supramolecular iridium(III) assemblies

Martir

Zysman‐Colman

2018

Coordination Chemistry Reviews

View full text Add to dashboard Cite

Iridium(III) complexes exhibit remarkable photophysical properties such as high photoluminescence quantum yields, wide color tunability and high chemical stability. They have featured prominently in diverse applications such as sensing, bio-imaging, photoredox catalysis, solar fuels and solid-state lighting. In the vast majority of these reports the iridium complex is mononuclear in nature. The use of iridium complexes as components of selfassembled systems has garnered increasing attention and this review aims to comprehensively document the advances made in this area. Special emphasis will be devoted to describing the photophysical properties and applications of such photo-active supramolecular materials. Soft materials such as soft salts, liquid crystals, gels, colloids incorporating iridium are described as are hydrogen bonding-and π-π staking-directed assemblies, coordination-driven selfassembled materials such as coordination polymers and metal organic frameworks, macrocycles, capsules and cages. Finally, guest Ir(III) complexes encapsulated within the cavities of cage-type structures are presented. Contents

show abstract

“…The bis‐tridentate Ir(III) complexes have been independently reported by Williams and co‐workers,14 De Cola and co‐workers,15 and Esteruelas et al16 However, inferior emission efficiency and lack of color tunability were the major weaknesses encountered to these earlier researches. To circumvent these obstacles, we set forth preparation of bis‐tridentate Ir(III) complexes using both pincer dicarbene and functional 6‐pyrazolyl‐2‐phenylpyridine (pzyph) as the ancillary and chromophoric chelates, respectively 17.…”

mentioning

confidence: 99%

Bis‐Tridentate Iridium(III) Phosphors with Very High Photostability and Fabrication of Blue‐Emitting OLEDs

et al. 2018

View full text Add to dashboard Cite

Sky‐blue and blue‐emitting, carbazolyl functionalized, bis‐tridentate Ir(III) phosphors Cz‐1–Cz‐3 with bright emission and short radiative lifetime are successfully synthesized in a one‐pot manner. They exhibit very high photostability against UV–vis irradiation in degassed toluene, versus both green and true‐blue‐emitting reference compounds, i.e., fac‐[Ir(ppy)3] and mer‐[Ir(pmp)3]. Organic light‐emitting diodes (OLEDs) based on Cz‐2 exhibit maximum external quantum efficiency (EQE) of 21.6%, EQE of 15.1% at 100 cd m−2, and with CIEx , y coordinates of (0.17, 0.25). This study provides a conceptual solution to the exceedingly stable and efficient blue phosphor. It is promising that long lifespan blue OLED based on these emitters can be attained with further engineering of devices suitable for commercial application.

show abstract

Cyclometallated, bis-terdentate iridium complexes as linearly expandable cores for the construction of multimetallic assemblies

Cited by 66 publications

References 45 publications

Bis‐Tridentate Ir(III) Metal Phosphors for Efficient Deep‐Blue Organic Light‐Emitting Diodes

Bis‐Tridentate Ir(III) Metal Phosphors for Efficient Deep‐Blue Organic Light‐Emitting Diodes

Supramolecular iridium(III) assemblies

Bis‐Tridentate Iridium(III) Phosphors with Very High Photostability and Fabrication of Blue‐Emitting OLEDs

Contact Info

Product

Resources

About