Jens K. Bjernemose

Synthesis, characterisation and optical spectroscopy of platinum(II) di-ynes and poly-ynes incorporating condensed aromatic spacers in the backbone

A series of protected and terminal dialkynes with extended pi-conjugation through a condensed aromatic linker unit in the backbone, 1,4-bis(trimethylsilylethynyl)naphthalene, 1,4-bis(ethynyl)naphthalene, 9,10-bis(trimethylsilylethynyl)anthracene, 9,10-bis(ethynyl)anthracene, have been synthesized and characterized spectroscopically. The solid-state structures of and have been confirmed by single crystal X-ray diffraction studies. Reaction of two equivalents of the complex trans-[Ph(Et(3)P)(2)PtCl] with an equivalent of the terminal dialkynes 1,4-bis(ethynyl)benzene and, in (i)Pr(2)NH-CH(2)Cl(2), in the presence of CuI, at room temperature, afforded the platinum(II) di-ynes trans-[Ph(Et(3)P)(2)Pt-C[triple bond, length as m-dash]C-R-C[triple bond, length as m-dash]C-Pt(PEt(3))(2)Ph](R = benzene-1,4-diyl; naphthalene-1,4-diyl and anthracene-9,10-diyl ) while reactions between equimolar quantities of trans-[((n)Bu(3)P)(2)PtCl(2)] and under similar conditions readily afforded the platinum(II) poly-ynes trans-[-((n)Bu(3)P)(2)Pt-C[triple bond]C-R-C[triple bond]C-](n)(R = naphthalene-1,4-diyl and anthracene-9,10-diyl ). The Pt(II) diynes and poly-ynes have been characterized by analytical and spectroscopic methods, and the single crystal X-ray structures of and have been determined. These structures confirm the trans-square planar geometry at the platinum centres and the linear nature of the molecules. The di-ynes and poly-ynes are soluble in organic solvents and readily cast into thin films. Optical spectroscopic measurements reveal that the electron-rich naphthalene and anthracene spacers create strong donor-acceptor interactions between the Pt(II) centres and conjugated ligands along the rigid backbone of the organometallic polymers. Thermogravimetry shows that the di-ynes possess a somewhat higher thermal stability than the corresponding poly-ynes. Both the Pt(II) di-ynes and the poly-ynes exhibit increasing thermal stability along the series of spacers from phenylene through naphthalene to anthracene.

Synthesis and characterisation of new acetylide-functionalised aromatic and hetero-aromatic ligands and their dinuclear platinum complexes

A new series of rigid rod protected and terminal dialkynes with extended π-conjugation through aromatic and hetero-aromatic linker units in the backbone, 2,5-bis(trimethylsilylethynyl)-1-(2-ethylhexyloxy)-4-methoxybenzene 1a, 2,5-bis(ethynyl)-1-(2-ethylhexyloxy)-4-methoxybenzene 1b, 5,8-bis(trimethylsilylethynyl)quinoline 2a, 5,8-bis(ethynyl)quinoline 2b, 2,3-diphenyl-5,8-bis(trimethylsilylethynyl)quinoxaline 3a, 2,3-diphenyl-5,8-bis(ethynyl)quinoxaline 3b, 4,7-bis(trimethysilylethynyl)-2,1,3-benzothiadiazole 4a and 4,7-bis(ethynyl)-2,1,3-benzothiadiazole 4b, has been synthesised. Treatment of the complex trans-[Pt(Ph)(Cl)(Et3P)2] with half an equivalent of the diterminal alkynes 1b–4b in iPr2NH–CH2Cl2, in the presence of CuI, at room temperature, afforded the platinum(II) di-yne complexes trans-[(Et3P)2(Ph)Pt–CC–R–CC–Pt(Ph)(Et3P)2] [R = 1-(2-ethylhexyloxy)-4-methoxybenzene-2,5-diyl 1c, quninoline-5,8-diyl 2c, 2,3-diphenylquinoxaline-5,8-diyl 3c, 2,1,3-benzothiadiazole-4,7-diyl 4c] in good yields. The new acetylide-functionalised ligands and the platinum(II) σ-acetylide complexes have been characterised by analytical and spectroscopic methods and X-ray single crystal structure determinations for 2c–4c. The absorption spectra of the complexes 2c–4c show substantial donor–acceptor interaction between the platinum(II) centres and the conjugated ligands. The photoluminescence spectra of 1c–3c show characteristic singlet (S1) and triplet (T1) emissions. Both the singlet and triplet emissions as well as the absorption decrease in energy with increasing electronegativity of the spacer groups along the series 1c–4c.

(2,2′-Bi­pyridine)­di­chloro­gold(III) nitrate

The title compound, [AuCl2(C10H8N2)]NO3, is layered parallel to (\overline 101) by π–π stacking. The individual {\overline 101} layers are held together by extensive C—H⋯O and C—H⋯Cl hydrogen bonding.

Trans-Bis(carbazol-3-ylethynyl)bis(tri-n-butylphosphine)platinum(II)

The title compound, [Pt(C12H27P)(2)(C14H8N)(2)], is a mononuclear Pt-II di-yne exhibiting pi-conjugation along the molecular backbone. It is used as a model species for rigid-rod platinum poly yne compounds of which it is a precursor. Such compounds are of interest due to the extended pi-conjugation through the hetero-aromatic linker unit in the backbone.

{4,4′-Di-tert-butyl-6,6′-bis­(di­methoxy­methyl)-2,2′-[propane-1,3-diyl­bis­(nitrilo­methyl­idyne)]­bis­(thio­phenolato)-κ4S,N,N′,S′}nickel(II)

The title compound, [Ni(C31H44N2O4S2)], is an N2S2 four-coordinated nickel(II) complex. The coordination geometry of the metal, on a twofold rotation axis, is more distorted from square planar than in related compounds.

Structural characterisation of a water intercalated bis-amide tecton and copper promoted monohydration of a dinitrile

Chains of H-bonded water intercalated bis-amide pairs were found in the structure of {[Cu(cdc)2(OH2)]·H2O}∞ (1) (cdc− = carbamoyldicyanomethanide); specific hydration of one nitrile group of the cdc− ligands of 1 to give the previously unknown anion cyanomalonamidate (cyma−) as a ligand in [Cu(cyma)2]·H2O is possible.

2,6-Bis(bis(pyridin-2-ylmethyl)aminomethyl)-4-tert-butylphenol

The title compound (Hbpbp), C36H40N6O, is a phenol with one intramolecular bifurcated hydrogen bond. This result furnishes an explanation as to why the otherwise symmetric deprotonated ligand shows a propensity for forming asymmetric, e.g. heterovalent and heterometallic, coordination compounds.

5-[(E)-2-Phenylethen-1-yl]-quinolin-8-ol.

The title compound, C17H13NO, dimerizes through O—H⋯N hydrogen bonds with H⋯N in the range 2.00–2.27 A. These dimers form an extended structure through π–π stacking and C—H⋯π interactions.

N,N‐Bis[2‐(2‐pyridyl)ethyl]­hydroxy­lamine

The crystal structure of the title compound, C14H17N3O, at 180 K contains intermolecular hydrogen bonds between the hydroxyl group and the N atom of one pyridyl ring.

2-Phenyl-1,3-bis(2-pyridyl­methyl)­imidazolidine

In the title compound, C21H22N4, all three substituents are found in equatorial positions. Intermolecular C—H⋯N and C—H⋯π interactions seem to be responsible for the packing.