Highly uniform and low-loss passive silicon photonics devices using a 300mm CMOS platform

Using an advanced 300mm CMOS-platform, we report record-low and highly-uniform propagation loss: 0.45 +/- 0.12dB/cm for wires, and 2dB/cm for slot waveguides. For WDM devices, we demonstrate channel variation(3-sigma) within-wafer and within-device of 6.1nm and 1.2nm respectively

Comparative studies of µ-oxo, µ-nitrido and µ-carbido diiron octapropylporphyrazine complexes and their catalytic activity in carbene transfer to olefins.

SSCI-VIDE+CDFA+LCL:ASONational audienceCarbene transfer reactions catalyzed by metal complexes are widely used in organic chemistry. Due to high versatility of this synthetic strategy involving metal carbene complexes, a large range of elaborated compounds can be prepared via cyclopropanation of olefins and carbene insertion into C-H, N-H and O-H bonds. Among the metal complexes, metalloporphyrins have been extensively studied as catalysts for the carbene transfer reactions. In contrast, their phthalocyanine and porphyrazine counterparts have been rarely used. We present here the first detailed study of application of µ-X bridged diiron porphyrazine complexes (X = O, N, C) for the intermolecular cyclopropanation of olefins. The electronic structure of the µ-oxo, µ-nitrido and µ-carbido complexes was studied by Mössbauer spectroscopy which confirmed the Fe(III)µOFe(III), Fe(+3.5)µNFe(+3.5) and Fe(IV)µCFe(IV) oxidation states.The influence of the catalyst bridging atom and the oxidation state of metal on the reactivity as well as the nature of substrate on cyclopropanation efficiency was investigated. µ-Oxo diiron complex exhibited the highest reaction rate and provided a 95 % yield of cyclopropanation products.Hammett correlation of the influence of the styrene para-substituents on the cyclopropanation rate for all dimeric complexes showed higher reactivity of styrenes having electron-donating substituents and better correlation with Sigma p+ parameters. While the µ-oxo and µ-carbido complexes showed a moderate linearity, no clear trend in the cyclopropanation of electron-rich and electron-deficient olefins was observed for µ-nitrido complex, suggesting the difference in the nature of the putative carbene complexes (µ-oxo and µ-carbido versus µ-nitrido) or/and in the mechanism of cyclopropanation.In conclusion, the nature of the bridging group determines the oxidation state of the diiron fragments and hence their reactivity in the carbene transfer reactions. This study showed a relationship between bridging atom trans effect and reaction rate and revealed the importance of the iron ligand on catalytic activity of porphyrinoid complexes

Mono- and binuclear iron phthalocyanine-like complexes: from bio-inspired oxidation to carbene transfer reactions.

SSCI-VIDE+CDFA+ASO:LCLInternational audienceMetal phthalocyanine complexes are efficient catalysts for a variety of reactions. Although phthalocyanines have been often considered as porphyrin analogues, their catalytic properties do differ from those of porphyrin counterparts. Moreover, increasing number of examples unambiguously shows that phthalocyanine complexes are superior in many reactions. Recent extensive studies showed that metallophthalocyanine complexes are efficient catalysts, in particular for biomimetic oxidation. In contrast to the porphyrin counterparts, phthalocyanine complexes are cheap and readily available on a very large scale (~100 000 t annual production) which makes these robust complexes viable for potential industrial applications. Our groups demonstrated that along with mononuclear complexes, binuclear diiron phthalocyanine complexes exhibit remarkable catalytic properties in the oxidation of alkanes including methane and ethane, C-C bond formation, oxidative defluorination and other reactions. Herein, we explore catalytic properties of iron and diiron phthalocyanine and related porphyrazine complexes in cyclopropanation and carbene transfer to N-H bonds of amines using ethyl diazoacetate carbene precursor. The electronic structure of these complexes and their putative carbene species was investigated by DFT calculations showing significant influence of the iron oxidation state and the nature of bridging atom. The relationship between electronic structure of the complex and their catalytic activity in carbene transfer reactions will be discussed

Diiron phthalocyanine complexes for challenging oxidation and carbene transfer reactions

SSCI-VIDE+CDURABLE+ASOInternational audienceGiven a high catalytic efficiency of diiron µ-nitrido complexes in oxidation, diiron species deserve more careful evaluation in the carbene transfer reactions. The carbene transfer reactivity is associated with the involvement of metal carbene intermediates which are isoelectronic to high-valent oxo species. Combined experimental and DFT studies showed that µ-oxo diiron complex Fe(III)–O–Fe(III) was more efficient in cyclopropanation of olefins compared to Fe(III)–N–Fe(IV) and Fe(IV)–C–Fe(IV) counterparts (Scheme 1). Electronic structures of three single atom bridged diiron complexes and their putative carbene species were studied. This detailed DFT study allowed to get insight into reactivity of binuclear carbene species and for the first time to confirm their involvement into carbene transfer reaction. The relationship between the reactivity and electronic properties will be discusse

Comparative studies of µ-oxo, µ-nitrido and µ-carbido diiron octapropylporphyrazine complexes and their catalytic activity in carbene transfer to olefins.

SSCI-VIDE+CDFA+LCL:ASONational audienceCarbene transfer reactions catalyzed by metal complexes are widely used in organic chemistry. Due to high versatility of this synthetic strategy involving metal carbene complexes, a large range of elaborated compounds can be prepared via cyclopropanation of olefins and carbene insertion into C-H, N-H and O-H bonds. Among the metal complexes, metalloporphyrins have been extensively studied as catalysts for the carbene transfer reactions. In contrast, their phthalocyanine and porphyrazine counterparts have been rarely used. We present here the first detailed study of application of µ-X bridged diiron porphyrazine complexes (X = O, N, C) for the intermolecular cyclopropanation of olefins. The electronic structure of the µ-oxo, µ-nitrido and µ-carbido complexes was studied by Mössbauer spectroscopy which confirmed the Fe(III)µOFe(III), Fe(+3.5)µNFe(+3.5) and Fe(IV)µCFe(IV) oxidation states.The influence of the catalyst bridging atom and the oxidation state of metal on the reactivity as well as the nature of substrate on cyclopropanation efficiency was investigated. µ-Oxo diiron complex exhibited the highest reaction rate and provided a 95 % yield of cyclopropanation products.Hammett correlation of the influence of the styrene para-substituents on the cyclopropanation rate for all dimeric complexes showed higher reactivity of styrenes having electron-donating substituents and better correlation with Sigma p+ parameters. While the µ-oxo and µ-carbido complexes showed a moderate linearity, no clear trend in the cyclopropanation of electron-rich and electron-deficient olefins was observed for µ-nitrido complex, suggesting the difference in the nature of the putative carbene complexes (µ-oxo and µ-carbido versus µ-nitrido) or/and in the mechanism of cyclopropanation.In conclusion, the nature of the bridging group determines the oxidation state of the diiron fragments and hence their reactivity in the carbene transfer reactions. This study showed a relationship between bridging atom trans effect and reaction rate and revealed the importance of the iron ligand on catalytic activity of porphyrinoid complexes

Mono- and binuclear iron phthalocyanine-like complexes: from bio-inspired oxidation to carbene transfer reactions.

SSCI-VIDE+CDFA+ASO:LCLInternational audienceMetal phthalocyanine complexes are efficient catalysts for a variety of reactions. Although phthalocyanines have been often considered as porphyrin analogues, their catalytic properties do differ from those of porphyrin counterparts. Moreover, increasing number of examples unambiguously shows that phthalocyanine complexes are superior in many reactions. Recent extensive studies showed that metallophthalocyanine complexes are efficient catalysts, in particular for biomimetic oxidation. In contrast to the porphyrin counterparts, phthalocyanine complexes are cheap and readily available on a very large scale (~100 000 t annual production) which makes these robust complexes viable for potential industrial applications. Our groups demonstrated that along with mononuclear complexes, binuclear diiron phthalocyanine complexes exhibit remarkable catalytic properties in the oxidation of alkanes including methane and ethane, C-C bond formation, oxidative defluorination and other reactions. Herein, we explore catalytic properties of iron and diiron phthalocyanine and related porphyrazine complexes in cyclopropanation and carbene transfer to N-H bonds of amines using ethyl diazoacetate carbene precursor. The electronic structure of these complexes and their putative carbene species was investigated by DFT calculations showing significant influence of the iron oxidation state and the nature of bridging atom. The relationship between electronic structure of the complex and their catalytic activity in carbene transfer reactions will be discussed