Muhammad Salahuddin Khan

Muhammad Salahuddin Khan
Sultan Qaboos University | SQU · Department of Chemistry

Doctor of Philosophy

About

162
Publications
13,361
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6,133
Citations
Citations since 2017
53 Research Items
1725 Citations
20172018201920202021202220230100200300400
20172018201920202021202220230100200300400
20172018201920202021202220230100200300400
20172018201920202021202220230100200300400

Publications

Publications (162)
Article
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The design and development of functional materials with real-life applications are highly demanding. Understanding and controlling inter- and intra-molecular interactions provide opportunities to design new materials. A judicious manipulation of the molecular structure significantly alters such interactions and can boost selected properties and fun...
Article
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Two new organo-europium complexes (OEuCs) [Eu(tfac)3(TB-Im)] (Eu1) [Eu(hfac)3(TB-Im)] (Eu2) incorporating fluorinated (hexafluoroacetylacetone; Hhfaa) or hemi-fluorinated (trifluoroacetylacetone; Htfac) β-diketones together with the large bite angle N^N ligand (2-(4-Thiazolyl)benzimidazole; TB-Im) have been synthesized and characterized. The struct...
Article
Full-text available
Domesticating solar energy by exploiting photovoltaic technology has become a quintessential strategy for future global energy production. Since 2015, non-fullerene organic solar cells (NF-OSC) have attracted a great deal of attention owing to the marvellous properties of non-fullerene acceptors (NFA) such as structural versability, broad absorptio...
Article
In the present work, we have described the structures, photo-physical properties and DFT computations of some curcumin type diarylheptanoids (4a-c). These compounds were characterized by multi-spectroscopic techniques including X-ray single crystal of one of the intermediates (3a). The molecular geometries and structural features were configured by...
Article
A series of tetrakis lanthanide complexes with the general formula [Ln(hfaa)4]-(DpaH)+ [Ln = (Sm-1), (Eu-1) and (Tb-1)], hfaa = hexafluroacetylacetonate and Dpa −2,2′-dipyridylamine] has been synthesized by the reaction of LnCl3, hfaa and Dpa in the presence ammonia solution (25%). The complexes have been characterized by analytical and spectroscop...
Chapter
Over the last decade the chemistry of conjugated poly (metalla-ynes) has developed substantially because of the usefulness of these materials in a range of applications including as sensors, memory devices, catalysts and biologically active materials. These metalla-yne polymers and their molecular precursors contain late heavy transition elements l...
Article
Full-text available
Metalla-ynes and poly(metalla-ynes) have emerged as unique molecular scaffolds with fascinating structural features and intriguing photo-luminescence (PL) properties. Their rigid-rod conducting backbone with tunable photo-physical properties has generated immense research interests for the design and development of application-oriented functional m...
Article
Two new octa-coordinated ternary europium(III) complexes of the type [Eu(btfa)3(Br2-bpy)] (Eu-1) and [Eu(btfa)3(PhE2-bpy)] (Eu-2) (where btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, Br2-bpy = 5,5′-dibromo-2,2′-bipyridine, PhE2-bpy 5,5′-bis(phenylethynyl)-2,2′-bipyridine) together with a previously reported complex [Eu(btfa)3(bpy)] (Eu-3) have b...
Article
We present the synthesis and characterization of seven new organic co-poly-ynes P1-P7 incorporating the phenothiazine (PTZ) motif and evaluate their optoelectronic properties and performance in polymer light-emitting diodes and polymer solar cells (PLEDs/PSCs). The co-poly-ynes were obtained in moderate to high yields via Sonogashira coupling react...
Article
Full-text available
Square planar organoplatinum(II) complexes have garnered immense interest in the area of materials research. The combination of the Pt(II) fragment with mono-, bi- tri- and tetradentate organic ligands gives rise to a large variety of complexes with intriguing properties, especially cyclometalated Pt(II) complexes in which ligands are connected thr...
Article
A new tris β-diketonate europium(III) complex [Eu(btfa)3Py-Im] (Eu-1) (4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa) and 2-(2-pyridyl)benzimidazole (Py-Im)] has been synthesized and structurally characterized. A single crystal X-ray diffraction analysis shows that Eu-1 is octacoordinated and the coordination sphere is composed of a EuO6N2 core wi...
Article
A series of mono-, di-, and poly(platina-ynes) incorporating stilbene spacer units with the formulae trans-[R-C≡C-Pt(PBu3)2-C≡C-R] (R = (E)-1,2-diphenylethene), trans-[(Ph)-(Et3P)2PtC≡C-R-C≡CPt(PEt3)2(Ph)] R = (E)-1,2-diphenylethene), and trans-[−(PnBu3)2PtC≡C-R-C≡C−]n (R = (E)-1,2-diphenylethene), respectively, have been synthesized and characteri...
Article
Pt(II) diynes and polyynes incorporating 5,5′- and 6,6′-disubstituted 2,2′-bipyridines were prepared following conventional Sonogashira and Hagihara dehydrohalogenation reaction protocols. Using Pt(II) dimers and polymers as a rigid-rod backbone, four new heterobimetallic compounds incorporating Re(CO)3Cl as a pendant functionality in the 2,2′-bipy...
Article
Full-text available
A new heterotrinuclear (d-f-d) complex [Eu(btfa)31c] (btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione and 1c = [(Ph)(Et3P)2Pt–C≡C–R–C≡C–Pt(Et3P)2(Ph)] (R = 2,2’-bipyridine-5,5’-diyl) has been synthesized by utilizing the N,N-donor sites of the organometallic chromophore. The complex was characterized by analytical and spectroscopic methods. Photoph...
Article
A new heterotrinuclear (d-f-d) complex [Eu(btfa)31c] (btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione and 1c = [(Ph)(Et3P)2Pt–C≡C–R–C≡C–Pt(Et3P)2(Ph)] (R = 2,2’-bipyridine-5,5’-diyl) has been synthesized by utilizing the N,N-donor sites of the organometallic chromophore. The complex was characterized by analytical and spectroscopic methods. Photoph...
Article
Full-text available
In the crystal structure of the title compound, [Cu4Cl6O(C13H9N)4], the core molecular structure consists of a Cu4 tetrahedron with a central interstitial O atom. Each edge of the Cu4 tetrahedron is bridged by a chlorido ligand. Each copper(II) cation is coordinated to the central O atom, two chlorido ligands and one N atom of the 4-phenylethynylpy...
Article
Boron-containing π-conjugated materials are archetypical candidates for a variety of molecular scale applications. The incorporation of boron into the π-conjugated frameworks significantly modifies the nature of the parent π-conjugated systems. Several novel boron-bridged π-conjugated materials with intriguing structural, photo-physical and electro...
Article
Full-text available
Boron-containing π-conjugated materials are archetypical candidates for a variety of molecular scale applications. The incorporation of boron into the π-conjugated frameworks significantly modifies the nature of the parent π-conjugated systems. Several novel boron-bridged π-conjugated materials with intriguing structural, photo-physical and electro...
Article
Full-text available
Inflammation is a hallmark of many metabolic diseases. We previously showed that ferrocene-appended 1H-1,2,3-triazole hybrids inhibit nitric oxide (NO) production in in vitro models of lipopolysaccharide-induced inflammation in the BV-2 cell. In the present study, we explored the viability, anti-inflammatory, and antioxidant potential of ferrocene-...
Article
A new homodinuclear complex [Eu(btfa)3]2bpm (1) was synthesized incorporating 4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa) as the primary and 2,2ʹ-bipyrimidine (bpm) as the auxiliary ligand. The complex was characterized by analytical and spectroscopic techniques, with special emphasis on the crystal structure and photoluminescence (PL) properti...
Article
The photophysical properties of two previously synthesized, highly efficient, bright red emitting complexes [Eu(btfa)3DPEPO] (CIE, 0.672; 0.326) (Eu-1) and [Eu(nta)3DPEPO] (CIE, 0.673; 0.326) (Eu-2) (btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, nta = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione and DPEPO= bis(2-(diphenylphosphino)phenyl)ether...
Article
he photophysical properties of two previously synthesized, highly efficient, bright red emitting complexes [Eu(btfa)3DPEPO] (CIE, 0.672; 0.326) (Eu-1) and [Eu(nta)3DPEPO] (CIE, 0.673; 0.326) (Eu-2) (btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, nta = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione and DPEPO = bis(2-(diphenylphosphino)phenyl)ether...
Article
A new samarium complex [Sm(hfaa)3(Py-Im)] (ML) was synthesized by utilizing hexafluoroacetylacetone (hfaa) and 2-(2-pyridyl)benzimidazole (Py-Im) as coordinating ligands. A single crystal X-ray analysis shows that in the solid-state the complex dimerizes through intermolecular hydrogen-bonding with N–H···O (2.127 Å) and N–H···F (2.576 Å) interactio...
Article
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Square planar platinum(II) complexes have been known for 150 years and pincer complexes, supported by a tridentate chelating ligand such as terpyridyl, have been known for more than 70 years. The development of cyclometallated platinum(II) pincer complexes, in which the tridentate ligand forms one or more platinum–carbon bonds, has been much more r...
Article
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Two new mixed ligand complexes [Eu(tfac)3(DPEPO)] (Eu-1) and [Tb(tfac)3(DPEPO)] (Tb-2) incorporating trifluoroacetylacetone (Htfac) and bis(2-(diphenylphosphino)phenyl) ether oxide (DPEPO) were synthesized in gram-scale quantities and used as emitters to fabricate single- and double- EML (light-emitting layer) electroluminescence (EL) devices. The...
Article
Phenothiazine is a butterfly shaped molecule endowed with remarkable electronic properties and functions. The photoluminescence, electroluminescence and electro-chemical properties of this molecule can be significantly modified by derivatization of the parent phenothiazine moiety. In the last few decades, this electroactive molecule and its derivat...
Article
New Eu(III) and La(III)/Schiff base complexes have been synthesized and fully characterized from the Schiff base ligand: L, (E)-N′-(pyridin-2-ylmethylene)acetohydrazide. The simple tri-aqua complex: [EuL2(H2O)3]Cl3 (EuL) emits intense red luminescence from the ⁵D0 level of Eu(III). The binding tendency of EuL and LaL, was investigated in solution f...
Article
A new Eu(III) complex, [Eu(tta)3DPA] (1) (tta = 2-Thenoyltrifluoroacetone and DPA = 2,2′-Dipyridylamine) has been synthesized and characterized by analytical and spectroscopic techniques. Photoluminescence (PL) studies of complex 1 were performed in the solid state and in a range of solvents to assess the effect of high energy oscillators on the PL...
Article
Two new lanthanide complexes [Ln(hfaa)3(Py-Im)] [hfaa = hexafluoroacetylacetone, Py-Im = 2-(2-pyridyl)benzimidazole and Ln = Eu(III) (1) and Tb(III) (2)] were synthesized and characterized. An X-ray crystal structure determination confirms that complex 1 is eight-coordinate with a distorted trigonal dodecahedral geometry. It shows typical vivid red...
Article
Mono-, di- and polynuclear metal alkynyl or σ-acetylide complexes have attracted a great deal of interest due to their multi-dimensional applications. In the past few decades, several small to medium sized neutral and charged metal acetylides have been synthesized and assessed for various biomedical applications. This review explores the progress m...
Article
Three new iodo-bridged copper(I) complexes of the type [CuI(PPh3)L]2, where L = Ar–≡–C5H4N, Ar = phenyl (C1), biphenyl (C2) and flourenyl (C3) have been synthesized via coordination-driven self-assembly processes. Two of Cu(I) complexes, C2 and C3, have been characterized by single-crystal X-ray diffraction studies. The complexes have two molecules...
Article
Two new octa-coordinated red emitting complexes of the type [Ln(acac) 3 (Br 2 -phen)] [acac: acetylacetonate, Br 2 -phen: 4,7-dibromo-1,10-phenanthroline, Ln: Sm(III) and Eu(III)] have been synthesized and characterized. Single crystal X-ray diffraction (SCXD) of [Eu(acac) 3 (Br 2 -phen)] and [Eu(acac) 3 (H 2 O) 2 ](H 2 O) revealed distorted square...
Article
Three highly luminescent Eu(III) complexes of the type [Eu(β-diket.)3(tm-phen)] where β-diket. = hexafluoroacetylacetone (hfaa), btfa; 4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa), 2-thenoyltrifluoroacetone (ttfa) and tm-phen=3,4,7,8-tetramethyl-1,10-phenanthroline have ben synthesized and characterized. The detailed photophysical properties of...
Article
Two hetero-trinuclear complexes of the type [Eu(btfa)3Pt2-bpy] and [Eu(nta)3Pt2-bpy] (where btfa and nta is the anion of 4,4,4-trifluoro-1-phenyl-1,3-butanedione; 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, respectively and Pt2bpy = trans-[(Ph)(Et3P)2Pt-C≡C-R-C≡C-Pt(PEt3)2(Ph)] (R = 2,2‘-Bipyridine-6,6‘-diyl) have been synthesized by the reacti...
Article
Heteroaryl incorporated acetylide-functionalized pyridinyl ligands (L1-L6) with the general formula Py-C≡C-Ar (Py = pyridine and Ar = thiophene-2-yl, 2,2' -bithiophene]-5-yl, 2,2' :5',2″ -terthiophene]-5-yl, thieno[2,3- b]thiophen-2-yl, quinoline-5-yl, benzo[c][1,2,5]thiadiazole-5-yl) have been synthesized by Pd(0)/Cu(I)-catalyzed cross-coupling re...
Article
Conjugated poly-ynes and poly(metalla-ynes) constitute an important class of new materials with potential application in various domains of science. The key factors responsible for the diverse usage of these materials is their intriguing and tunable chemical and photophysical properties. This review highlights fascinating advances made in the field...
Article
Copper(I) [Cu(I)] complexes offer cheap and alternative materials for several real-life applications. Pyridine (Py), bipyridine (Bpy) and related analogues have strong donating ability with propensity to ease functionalization via modern synthetic protocols. A large number of Cu(I) complexes/clusters/polymers bearing functionalized Py-based ligands...
Article
Organic photovoltaic (OPV) materials, especially small molecule donor materials (SMDMs) have enormous potential to revolutionize the solar energy sector. However, to be a viable alternative to the polymer donor counterparts, SMDMs must have high power conversion efficiency (PCE). A large number of different SMDMs have been reported, which have cros...
Article
Band-gap (Eg) of a material is an important criterion for application in opto-electronic (O-E) devices.1,2 Both low- and high Eg materials are useful and being synthesized by chemists via core structure modification, functional group variation and metal incorporation.3,4 We present herein computational study on the impact of incorporation of a Re(I...
Article
This review gives an account of the coordination chemistry, metallo-supramolecular chemistry and application of mono- and oligopyridine-based macrocyclic ligands. For this purpose, recently reported ligands and their metal complexes possessing at least one pyridyl donor group in a cyclic structure as the metal binding site have been selected. The a...
Article
A series of ferrocene-1H-1,2,3-triazole hybrids namely 1-(4-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (1), 1-(4,4′-dinitro-2-biphenyl)-4-ferrocenyl-1H-1,2,3-triazole (2), 1-(3-chloro-4-fluorophenyl)-4-ferrocenyl-1H-1,2,3-triazole (3), 1-(4-bromophenyl)-4-ferrocenyl-1H-1,2,3-triazole (4) and 1-(2-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (5) wer...
Article
Conjugated polymer solar cells (PSCs) use the principle of exciton dissociation at the interface of suitable donor and acceptor materials. However, this requires good phase separation between the two materials, which is often difficult to achieve. To circumvent such difficulties, we have covalently attached a C60 derivative (C60-DNF) to a Pt(II) po...
Article
Background: Throughout the history of human civilizations, cancer has been a major health problem. Despite the advancements made by modern medical sciences, complete treatment or removal of cancerous cells is still a challenging task. Vinblastine, an alkaloid obtained from Catharanthus roseus (L.) G. Don is one of the prominent antineoplastic agen...
Article
Ionic liquids (ILs) are emerging class of low-melting solid which have potential to replace conventional solvents. DNA is one of the primary targets of many synthetic agents which are classified as carcinogens; most of them bind to the DNA irreversible manner causing mutation of the genome. Thus, it is essential to study the nature and mode of bind...
Article
Background: In the quest for sustainable energy materials, new donor and acceptor materials are being designed, synthesized and tested for photovoltaic (PV) applications. In this context, conjugated organic polymers have received significant interests in the last few decades. Objective: In the present work, we synthesized an organic poly-yne P and...
Article
Cancer is a group of diseases responsible for the major causes of mortality and morbidity among people of all ages. Even though medical sciences have made enormous growth, complete treatment of this deadly disease is still a challenging task. Last few decades witnessed an impressive growth in the design and development of near infrared (NIR) fluoro...
Article
Trimethylsilyl-protected dialkynes incorporating azobenzene linker groups, Me3SiC≡CRC≡CSiMe3 (R = azobenzene-3,3′-diyl, azobenzene-4,4′-diyl, 2,5-dioctylazobenzene-4,4′-diyl), and the corresponding terminal dialkynes, HC≡CRC≡CH, have been synthesized and characterized. The CuI-catalyzed dehydrohalogenation reaction between trans-[Ph(Et3P)2PtCl] and...
Conference Paper
Photocell Studies of a Low Band-gap Blue Polymer/Perylene Dye Blend, Proceedings
Conference Paper
New series of Pt(II) di-ynes and poly-ynes incorporating a meta- and para-azobenzene and carbazole have been synthesized and characterized. The synthesis, spectroscopic, structural and photo-physical characterization of these new materials will be presented. Computational studies of model Pt(II) di-yne complexes show that compounds incorporating pa...
Article
Solar cells (SCs) are of considerable current research interest because of their potential as a clean alternative to fossil fuels. Researchers across the globe are developing novel polymeric materials with enhanced power conversion efficiency (PCE). Conjugated poly-ynes and poly(metalla-ynes) incorporating late transition metals and thiophene-based...
Article
Full-text available
Complexes of anionic pentadentate macrocyclic ligands by the template condensation of bis(hydrazino)2,2'-bipyridine or 1,10-phenanthroline with an indoledialdehyde have been synthesized. The new Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) macrocyclic complexes have been characterized by analytical and spectroscopic techniques and by conductiv...
Article
The importance of C-H bond activation in a simple molecule to form a molecule with enhanced functionality can be easily understood from a study of biological processes at a molecular level where, for example, a specific enzyme selectively activates a chemically inert C-H bond and functionalises it to a useful product. This strategy is now being use...
Article
Full-text available
A new series of Co(II) complexes of the type CoLX2 , where Lis a tetra-dentate ligand 8,8'-bis(aminomethyl)-2,2'-biquinoline and X= SCN–, BF4–, I– or NO3– , have been synthesized and characterized. The complexes have magnetic moments in the range typical of a low-spin d7 Co(II) center. The interaction of these Co(II) complexes with dioxygen was stu...
Article
Full-text available
Three new neutral di-ferrocenyl-ethynylpyridinyl copper complexes, [L2(CuCl)2(PPh3)2] (), [L2(CuBr)2(PPh3)2] (), and [L2(CuI)2(PPh3)2] () were synthesized from the ferrocenyl-ethynylpyridine ligand (L) (), the appropriate copper halide CuX (with X = Cl(-), Br(-), I(-)) and triphenylphosphine. These neutral complexes were fully characterized by spec...
Article
Full-text available
Ferrocenylethynyl is a key starting material for the synthesis of fascinating new molecules and novel functional materials. It combines the robust and redox-active ferrocene moiety with the rigid-rod ethynyl unit. The ferrocene center provides chemically and electrochemically switchable material properties whereas the ethynyl backbone facilitates e...
Data
Full-text available
Three new tetra-ferrocenylethynylpyridinyl copper complexes, L4(CuI)4 (3), L4(CuBr)2 (4), and L4(CuCl)2 (5) have been prepared from the reaction of ferrocenylethynylpyridine (L)(2) with copper halides CuX (with X = I–, Br–, Cl–).The ligand 2 and the complexes 3–5 have been fully characterized by spectroscopic methods. The structures of 2–4 have bee...
Article
Three new tetra-ferrocenylethynylpyridinyl copper complexes, L4(CuI)4 (3), L4(CuBr)2 (4), and L4(CuCl)2 (5) have been prepared from the reaction of ferrocenylethynylpyridine (L)(2) with copper halides CuX (with X = I(-), Br(-), Cl(-)).The ligand 2 and the complexes 3-5 have been fully characterized by spectroscopic methods. The structures of 2-4 ha...
Article
A new series of bis(ferrocenylethynyl) complexes, 3-7, and a mono(ferrocenylethynyl) complex, 8, have been synthesized incorporating conjugated heterocyclic spacer groups, with the ethynyl group facilitating an effective long-range intramolecular interaction. The complexes were characterized by NMR, IR, and UV-vis spectroscopy as well as X-ray crys...
Article
Full-text available
The intrinsic non-radiative decay (internal conversion) from the triplet excited state in phosphorescent dyes can be described by a multi-phonon emission process. Since non-radiative decay of triplet excitons can be a significant process in organic light-emitting diodes, a detailed understanding of this decay mechanism is important if the overall d...
Article
Full-text available
A series of trimethylsilyl-protected di-alkynes incorporating 3,4-ethylenedioxythiophene (EDOT) linker groups Me(3)Si-C≡C-R-C≡C-SiMe(3) (R = ethylenedioxythiophene-3,4-diyl 1a, 2,2'-bis-3,4-ethylenedioxythiophene-5,5'-diyl 2a, 2,2',5',2''-ter-3,4-ethylenedioxythiophene-5,5''-diyl 3a) and the corresponding terminal di-alkynes, H-C≡C-R-C≡C-H 1b-2b ha...
Article
Full-text available
A series of trimethylsilyl-protected di-alkynes incorporating 3,4-ethylenedioxythiophene (EDOT) linker groups Me3Si–C[triple bond, length as m-dash]C–R–C[triple bond, length as m-dash]C–SiMe3 (R = ethylenedioxythiophene-3,4-diyl 1a, 2,2′-bis-3,4-ethylenedioxythiophene-5,5′-diyl 2a, 2,2′,5′,2′′-ter-3,4-ethylenedioxythiophene-5,5′′-diyl 3a) and the c...
Article
The synthesis and characterization of the thieno[3,2-b]thiophene and dithieno[3,2-b:2′,3′-d]thiophene containing platinum(II) poly-ynes and their molecular precursors is described and the electronic structure is established by absorption, luminescence and photoinduced absorption measurements. A comparison of the electronic structure of the fused an...
Article
Full-text available
Efficient triplet exciton emission has allowed improved operation of organic light-emitting diodes LEDs. To enhance the device performance, it is necessary to understand what governs the motion of triplet excitons through the organic semiconductor. Here, we have investigated triplet diffusion using a model compound that has weak energetic disorder....
Article
The reaction of 2equiv. of [Os3(CO)10(MeCN)2] with R–CC–L–CC–R (R=H, L=(C4H2S); R=SiMe3, L=(C4H2S–C4H2S), (C4H2S–C4H2S–C4H2S), (C4H2S)–(C14H8)–(C4H2S)) affords the series of linked clusters [{Os3(CO)10}(HCC(C4H2S)CCH){Os3(CO)10}] (1), [{Os3(CO)10}(Me3SiCC(C4H2S–C4H2S)CCSiMe3){Os3(CO)10}] (2), [{Os3(CO)10}(Me3SiCC(C4H2S–C4H2S–C4H2S)CCSiMe3){Os3(CO)1...
Article
Full-text available
A series of novel platinum-containing carbazole monomers and polymers was synthesized and fully characterized by UV-VIS absorption, luminescence, and photoinduced absorption studies. In these compounds, a carbazole unit is incorporated into the main chain via either a para- or a meta-linkage. We discuss the effects of linkage and polymerization on...