Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/53587
Share/Export:
logo share SHARE logo core CORE BASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE
Title

One-pot and step-by-step N-assisted CPh-H activation in 2-(4-bromophenyl)imidazol[1,2-a]pyridine: Synthesis of a new C,N-cyclometalated compound [{Pt(C^N)(μ-CI)}2] as precursor of luminescent platinum(II) compounds

AuthorsForniés, Juan CSIC; Sicilia, Violeta CSIC ORCID; Larraz, Carmen CSIC; Camerano, José A. CSIC; Martín, Antonio CSIC ORCID; Casas, José M. CSIC ORCID; Tsipis, Athanassios C.
Issue Date2010
PublisherAmerican Chemical Society
CitationOrganometallics 29(6): 1396-1405 (2010)
AbstractThe activation of a. Cph-H bond in the phenyl ring of 2-(4-bromophenyl)imidazol[1,2-a]pyridine (HĈN)by[{Pt(n3-C 4H7)(μ-Cl)}2](n3-C 4H7 = n3-2-methylallyl) renders the new cyclometalated complex [{Pt(ĈN)(μ-Cl)}2] (2) with high yield and selectivity. Complex 2 can be achieved directly in a one-pot reaction or step by step through the intermediate [Pt(n3-C4H 7)Cl(HĈN-kN)] (1). Compound 1 could be isolated and fully characterized. The X-ray structure shows the coordination of HC ̂N through only the N and the existence of a weak Pt⋯-H-C hydrogen bridging bond (Pt⋯H1 =2.78 Å, Pt⋯Cl = 3.365(3) A, Pt-H1-C1. = 120.9°). Hence, the formation of this intermediate could be considered the first step in the cyclometalation process. The mononuclear complexes [PtCl(ĈN)L] (L = tht (3), PPh3 (4), CN-Xy1 (5), CN-tBu (6)) were obtained by cleavage of the bridging system in [{Pt(ĈN)(μ-Cl)}2] (2) by the neutral ligands, L. The resulting geometry (trans C, Cl) is that, expected, from the electronic preferences, taking into account the degree of transphobia (T) of pairs of trans ligands, T[C(ĈN)/L(C1)] < T[C(ĈN)/L(S, P, C)]. Complexes [PtCl(C^circ;N)L] (L = CN-XyI (5), CN- tBu (6)) containing two strong-field ligands, a CĉN σbonded and an isocyanide ligand, are luminescent. TD-DFT calculations were performed for the singlet ground state, So, as well as for the first triplet excited state of 6 in both the gas phase and solution. Calculations indicate that the lowest-lying absorption involves mainly 1IL (ĈN) mixed with, a small contribution of 1MLCT/1L'LCT (L = CAN; L' = Cl) transitions. Complex 5 exhibits >luminescent thermochromism> in the solid state; at. 77 K it shows a green phosphorescence band assigned to 3IL transitions located on the ĈN group of monomer species, while at 298 K an orange-red emission is observed, being tentatively assigned, to excited states of emissive aggregates (3MMLCT/3 π-π). However complex 6 shows phosphorescence only at 77 K both, in solution and in the solid state with the emissions arising from 3IL and 3L'MLCT excited states of monomer species. © 2010 American Chemical Society.
URIhttp://hdl.handle.net/10261/53587
DOI10.1021/om901032v
Identifiersdoi: 10.1021/om901032v
issn: 0276-7333
e-issn: 1520-6041
Appears in Collections:(ICMA) Artículos

Files in This Item:
File Description SizeFormat
accesoRestringido.pdf15,38 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work

SCOPUSTM   
Citations

19
checked on Jan 17, 2022

WEB OF SCIENCETM
Citations

19
checked on Jan 19, 2022

Page view(s)

256
checked on Jan 20, 2022

Download(s)

76
checked on Jan 20, 2022

Google ScholarTM

Check

Altmetric

Dimensions


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.