Alkynyl compounds and nonlinear optics

Bis(acetylido) Complexes of Ruthenium(II) Bearing Monodentate Phosphane Ligands

“…Interest stems from the potential applications of these complexes in many areas of material science, notably in the fields of nonlinear optics, [1,2] luminescence, [3] liquid-crystalline materials, [4] and molecular electronics. [5][6][7] The metal acetylide fragment possesses a π-bonding system that facilitates electronic communication between the conjugated organic ligand and the metal centre, with the possibility of extended π-electron conjugation conceivably providing a mechanism for electronic communication between remote metal centres.…”

“…[6,7] Additionally, the presence of transition metals in a polymer or oligomer backbone allows the electrochemical and spectroscopic properties to be tuned through changes in the metal ion and ancillary ligands. [7,8] The reaction of terminal acetylenes with simple iron(II) and ruthenium(II) precursors e. g. MH 2 (dmpe) 2 [M = Fe, Ru; dmpe = 1,2-bis(dimethylphosphanyl)ethane] is known [9,10] to yield symmetrical bis(acetylido) complexes, whereas the deprotonation of (vinylidene)ruthenium(II) complexes has emerged as a powerful and versatile route for the formation of both symmetrical and unsymmetical bis(acetylido) complexes. [2,11] Other routes to transition-metal acetylido complexes include the reaction of alkynylstannanes with metal halides, [12] and the reaction of lowvalent metals with terminal alkynes [13,14] or alkynyl(phenyl)-iodonium reagents.…”

“…[7,8] The reaction of terminal acetylenes with simple iron(II) and ruthenium(II) precursors e. g. MH 2 (dmpe) 2 [M = Fe, Ru; dmpe = 1,2-bis(dimethylphosphanyl)ethane] is known [9,10] to yield symmetrical bis(acetylido) complexes, whereas the deprotonation of (vinylidene)ruthenium(II) complexes has emerged as a powerful and versatile route for the formation of both symmetrical and unsymmetical bis(acetylido) complexes. [2,11] Other routes to transition-metal acetylido complexes include the reaction of alkynylstannanes with metal halides, [12] and the reaction of lowvalent metals with terminal alkynes [13,14] or alkynyl(phenyl)-iodonium reagents. [15] The reaction of alkyl transition-metal complexes and terminal alkynes by a σ-bond metathesis with concomitant loss of methane has been used to prepare complexes of Rh I [14,16] and Co I .…”

“…[15] The reaction of alkyl transition-metal complexes and terminal alkynes by a σ-bond metathesis with concomitant loss of methane has been used to prepare complexes of Rh I [14,16] and Co I . [17] We have previously reported the successful synthesis of unsymmetrically substituted iron(II) bis(acetylido) complexes by a σ-bond metathesis reaction between trans-Fe(CϵCR)Me(dmpe) 2 and a terminal alkyne, [18] and more recently have shown that the stepwise reaction of trans-RuMe 2 (dmpe) 2 firstly with one acetylene then with another can lead to sequential reaction of the methyl groups, and this provides a synthetic approach to both symmetrical and unsymmetrical bis(acetylido) complexes in good yield. [19] In this paper we examine the σ-bond metathesis reaction of cis-RuMe 2 (PMe 3 ) 4 with terminal acetylenes as a clean and effective route to ruthenium bis(acetylides) Ru(CϵCR) 2 -(PMe 3 ) 4 .…”

On the Role of Chalcogen Donor Atoms in Diimine‐Dichalcogenolate PtII SONLO Chromophores: Is It Worth Replacing Sulfur with Selenium?

“…Quantum yields were determined relative to anthracene in ethyl alcohol (C = 1-5·10 -6 M; exc = 334-359 nm), by calculating the integrated emission intensity of both the sample and the reference through a decomposition of the spectra in their constituent Gaussian curves. Spectral decomposition was carried out by means of the software 18 The total static second-order (quadratic) hyperpolarizability (the first hyperpolarizability) 19 tot was calculated as described previously. See Table S5 for translation of symmetry code to equivalent positions.…”