- NSF-PAR ID:
- 10163862
- Date Published:
- Journal Name:
- Australian Journal of Chemistry
- Volume:
- 70
- Issue:
- 4
- ISSN:
- 0004-9425
- Page Range / eLocation ID:
- 373
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)Copper(I) iodide complexes are well known for displaying a diverse array of structural features even when only small changes in ligand design are made. This structural diversity is well displayed by five copper(I) iodide compounds reported here with closely related piperidine-2,6-dithione (SNS), isoindoline-1,3-dithione (SNS6), and 6-thioxopiperidin-2-one (SNO) ligands: di-μ-iodido-bis[(acetonitrile-κ N )(6-sulfanylidenepiperidin-2-one-κ S )copper(I)], [Cu 2 I 2 (CH 3 CN) 2 (C 5 H 7 NOS) 2 ] ( I ), bis(acetonitrile-κ N )tetra-μ 3 -iodido-bis(6-sulfanylidenepiperidin-2-one-κ S )- tetrahedro -tetracopper(I), [Cu 4 I 4 (CH 3 CN) 4 (C 5 H 7 NOS) 4 ] ( II ), catena -poly[[(μ-6-sulfanylidenepiperidin-2-one-κ 2 O : S )copper(I)]-μ 3 -iodido], [CuI(C 5 H 7 NOS)] n ( III ), poly[[(piperidine-2,6-dithione-κ S )copper(I)]-μ 3 -iodido], [CuI(C 5 H 7 NS 2 )] n ( IV ), and poly[[(μ-isoindoline-1,3-dithione-κ 2 S : S )copper(I)]-μ 3 -iodido], [CuI(C 8 H 5 NS 2 )] n ( V ). Compounds I and II crystallize as discrete dimeric and tetrameric complexes, whereas III , IV , and V crystallize as polymeric two-dimensional sheets. To the best of our knowledge, compound III is the first instance of an extended hexagonal [Cu 3 I 3 ] structure that is not supported by bridging ligands. Structures I , II , and IV display weak to moderately strong Cu...Cu cuprophilic interactions [Cu...Cu internuclear distances range between 2.5803 (10) and 2.8485 (14) Å]. All structures except III display weak hydrogen-bonding interactions between the N—H of the ligand and the μ 2 and μ 3 -I − atoms. Structure III contains classical N–H...O interactions between the SNO ligands that connect the molecules in a three-dimensional framework. Complex V features π–π stacking interactions between the aryl rings of the SNS6 ligands within the same polymeric sheet. In structure IV , there were three partially occupied solvent molecules of dichloromethane and one partially occupied molecule of acetonitrile present in the asymmetric unit. The SQUEEZE routine [Spek (2015). Acta Cryst . C 71 , 9–18] was used to correct the diffraction data for diffuse scattering effects and to identify the solvent molecules. The given chemical formula and other crystal data do not take into account the solvent molecules.more » « less
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null (Ed.)Described herein is the synthesis and characterization of macrocyclic Cr III mono-alkynyl complexes. By using the meso -form of the tetraazamacrocycle HMC (HMC = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane), trans -[Cr(HMC)(C 2 Ph)Cl]OTf ( 1a ), trans -[Cr(HMC)(C 2 Np)Cl]OTf ( 2a ), trans -[Cr(HMC)(C 2 C 6 H 4 t Bu)Cl]OTf ( 3a ), and trans -[Cr(HMC)(C 2 (3,5-Cl 2 C 6 H 3 ))Cl]OTf ( 4a ) complexes have been realized. These complexes were synthesized in high yield through the reaction of trans -[Cr( meso -HMC)(C 2 Ar) 2 ]OTf ( 1b–4b ) with stoichiometric amounts of methanolic HCl. Single crystal X-ray diffraction showed that the trans -stereochemistry and pseudo-octahedral geometry is retained in the desired mono-alkynyl complexes. The absorption spectra of complexes 1a–4a display d–d bands with distinct vibronic progressions that are slightly red shifted from trans -[Cr(HMC)(C 2 Ar) 2 ] + with approximately halved molar extinction coefficients. Time-delayed measurements of the emission spectra for complexes 1a–4a at 77 K revealed phosphorescence with lifetimes ranging between 343 μs ( 4a ) and 397 μs ( 1a ). The phosphorescence spectra of 1a–4a also exhibit more structuring than the bis-alkynyl complexes due to a strengthened vibronic coupling between the Cr III metal center and alkynyl ligands.more » « less
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Abstract A pre‐formed Meisenheimer complex of a naphthalenediimide (NDI) with tetrabutylammonium fluoride (TBAF) is obtained in a simple way by mixing dibrominated 4,9‐dibromo‐2,7‐bis(2‐octyldodecyl)benzo[lmn][3,8]phenanthroline‐1,3,6,8(2H,7H)‐tetraone and TBAF in solution and used as a dopant for n‐type organic thermoelectrics. Two n‐type polymers PNDIClTVT and PBDOPVTT are synthesized, n‐doped, and characterized as conductive and thermoelectric materials. PNDIClTVT doped with NDI‐TBAF presents a high σ value of 0.20 S cm–1, a Seebeck coefficient (
S ) of −1854 µV K–1, and a power factor (PF) of 67 µW m–1K–2, among the highest reported PF in solution‐processed conjugated n‐type polymer thermoelectrics. Using 4‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzoimidazol‐2‐yl)phenyl)dimethylamine and NDI‐TBAF as co‐dopants, PNDIClTVT has a PF > 35 µW m–1K–2; while for PBDOPVTT σ = 0.75 S cm–1and PF = 58 µW m–1K–2. In this study it is found that an ionic adduct together with a neutral dopant improves the performance of n‐type organic thermoelectrics leading to an enhanced power factor, and more generally, the role of such an adduct in polymer doping is also elucidated. -
Abstract 3,3′,5,5′‐Tetra‐
tert ‐butyl‐2′‐sulfanyl[1,1′‐biphenyl]‐2‐ol (H2[t Bu4OS]) was prepared in 24 % yield overall from the analogous biphenol using standard techniques. Addition of H2[t Bu4OS] to Mo(NAr)(CHCMe2Ph)(2,5‐dimethylpyrrolide)2led to formation of Mo(NAr)(CHCMe2Ph)[t Bu4OS], which was trapped with PMe3to give Mo(NAr)(CHCMe2Ph)[t Bu4OS](PMe3) (1 (PMe3)). An X‐ray crystallographic study of1 (PMe3) revealed that two structurally distinct square pyramidal molecules are present in which the alkylidene ligand occupies the apical position in each. Both1 (PMe3)Aand1 (PMe3)Bare disordered. Mo(NAd)(CHCMe2Ph)(t Bu4OS)(PMe3) (2 (PMe3); Ad=1‐adamantyl) and W(NAr)(CHCMe2Ph)(t Bu4OS)(PMe3) (3 (PMe3)) were prepared using analogous approaches.1 (PMe3) reacts with ethylene (1 atm) in benzene within 45 minutes to give an ethylene complex Mo(NAr)(t Bu4OS)(C2H4) (4 ) that is isolable and relatively stable toward loss of ethylene below 60 °C. An X‐ray study shows that the bond distances and angles for the ethylene ligand in4 are like those found for bisalkoxide ethylene complexes of the same general type. Complex1 (PMe3) in the presence of one equivalent of B(C6F5)3catalyzes the homocoupling of 1‐decene, allyltrimethylsilane, and allylboronic acid pinacol ester at ambient temperature.1 (PMe3),2 (PMe3), and3 (PMe3) all catalyze the ROMP ofrac ‐endo ,exo ‐5,6‐dicarbomethoxynorbornene (rac ‐DCMNBE) in the presence of B(C6F5)3, but the polyDCMNBE that is formed has a random structure. -
The potential of pyrimidines to serve as ditopic halogen-bond acceptors is explored. The halogen-bonded cocrystals formed from solutions of either 5,5′-bipyrimidine (C 8 H 6 N 4 ) or 1,2-bis(pyrimidin-5-yl)ethyne (C 10 H 6 N 4 ) and 2 molar equivalents of 1,3-diiodotetrafluorobenzene (C 6 F 4 I 2 ) have a 1:1 composition. Each pyrimidine moiety acts as a single halogen-bond acceptor and the bipyrimidines act as ditopic halogen-bond acceptors. In contrast, the activated pyrimidines 2- and 5-{[4-(dimethylamino)phenyl]ethynyl}pyrimidine (C 14 H 13 N 3 ) are ditopic halogen-bond acceptors, and 1:1 halogen-bonded cocrystals are formed from 1:1 mixtures of each of the activated pyrimidines and either 1,2- or 1,3-diiodotetrafluorobenzene. A 1:1 cocrystal was also formed between 2-{[4-(dimethylamino)phenyl]ethynyl}pyrimidine and 1,4-diiodotetrafluorobenzene, while a 2:1 cocrystal was formed between 5-{[4-(dimethylamino)phenyl]ethynyl}pyrimidine and 1,4-diiodotetrafluorobenzene.more » « less