title: Substitution of Tetracyanoethene by Ethynyl–Metal Complexes Gives Tricyanovinylethynyl (Tricyanobutenynyl) Derivatives: Syntheses, Protonation, and Addition of Metal–Ligand Fragments

authors: Bruce, Michael I.

subjects: chemistry

abstract: A series of complexes containing the new tricyanovinylethynyl (3,4,4-tricyanobut-3-en-1-ynyl) ligand have been obtained by substitution of a CN group in tetracyanoethene upon reaction with the ethynyl complexes M(C≡CH)(PP)Cp′ (M = Ru, Os, (PP)Cp′ = (PPh3)2Cp; M = Ru, PP = dppe, Cp′ = Cp, Cp*). The reactions proceed in higher yield as the metal environment becomes more sterically hindered, the normal [2 + 2]-cycloaddition/ring-opened product M{C[═C(CN)₂]CH═C(CN)₂}(PP)Cp′ also being formed in some cases. The diynyl complex Ru(C≡CC≡CH)(dppe)Cp* reacts with tcne to give only the ring-opened adduct Ru{C≡CC[═C(CN)₂]CH═C(CN)₂}(dppe)Cp*. Protonation (HBF₄ or HPF₆) of Ru{C≡CC(CN)═C(CN)₂}(dppe)Cp* afforded the vinylidene cation [Ru{═C═CHC(CN)═C(CN)₂}(dppe)Cp*]⁺. A second transition-metal fragment MLn (MLn = Ru(PPh₃)₂Cp, M′(dppe)Cp* (M′ = Ru, Os), RuCl(dppe)₂) can be added to the CN group trans to the metal center; electrochemical, spectroscopic, and computational studies indicate that there is little ground-state delocalization between the metal centers. In the case of the tricyanovinylethynyl derivatives, an intense MLCT (or ML—LCT) transition can be identified in the visible region, which is responsible for the intense blue to purple color of these species; the analogous transition in the vinylidene-based complexes is significantly blue-shifted. The X-ray crystallographically determined structures of several of these complexes are reported. The cations [{Cp*(dppe)Ru}{μ-(C/N)≡CC(CN)═C(CN)(≡C/N)}{M(dppe)Cp*}]⁺ (M = Ru, Os) show some C≡C/C≡N disorder (and associated Ru/Os disorder in the case of the heterometallic example) in the crystals.

text: Substitution of Tetracyanoethene by Ethynyl–Metal Complexes Gives Tricyanovinylethynyl (Tricyanobutenynyl) Derivatives: Syntheses, Protonation, and Addition of Metal–Ligand Fragments A series of complexes containing the new tricyanovinylethynyl (3,4,4-tricyanobut-3-en-1-ynyl) ligand have been obtained by substitution of a CN group in tetracyanoethene upon reaction with the ethynyl complexes M(C≡CH)(PP)Cp′ (M = Ru, Os, (PP)Cp′ = (PPh3)2Cp; M = Ru, PP = dppe, Cp′ = Cp, Cp*). The reactions proceed in higher yield as the metal environment becomes more sterically hindered, the normal [2 + 2]-cycloaddition/ring-opened product M{C[═C(CN)₂]CH═C(CN)₂}(PP)Cp′ also being formed in some cases. The diynyl complex Ru(C≡CC≡CH)(dppe)Cp* reacts with tcne to give only the ring-opened adduct Ru{C≡CC[═C(CN)₂]CH═C(CN)₂}(dppe)Cp*. Protonation (HBF₄ or HPF₆) of Ru{C≡CC(CN)═C(CN)₂}(dppe)Cp* afforded the vinylidene cation [Ru{═C═CHC(CN)═C(CN)₂}(dppe)Cp*]⁺. A second transition-metal fragment MLn (MLn = Ru(PPh₃)₂Cp, M′(dppe)Cp* (M′ = Ru, Os), RuCl(dppe)₂) can be added to the CN group trans to the metal center; electrochemical, spectroscopic, and computational studies indicate that there is little ground-state delocalization between the metal centers. In the case of the tricyanovinylethynyl derivatives, an intense MLCT (or ML—LCT) transition can be identified in the visible region, which is responsible for the intense blue to purple color of these species; the analogous transition in the vinylidene-based complexes is significantly blue-shifted. The X-ray crystallographically determined structures of several of these complexes are reported. The cations [{Cp*(dppe)Ru}{μ-(C/N)≡CC(CN)═C(CN)(≡C/N)}{M(dppe)Cp*}]⁺ (M = Ru, Os) show some C≡C/C≡N disorder (and associated Ru/Os disorder in the case of the heterometallic example) in the crystals.

year: 2011

title: Teachers of English in Taiwanese primary schools reflect on their in-service training

authors: Wang, Wei Pei

subjects: Taiwan

abstract: We report here on the responses of a sample of ten teachers in primary/ elementary schools in Taiwan to that part of a survey (based on a written questionnaire and semi-structured interview) that related to their experiences of in-service training provision in the teaching of English. Most of the in-service training that this sample of teachers had been exposed to was in the form of one-off workshops (offered by textbook publishers, local government and cram schools). Responses to these workshops were mixed. The most negative responses related to workshops provided by publishers and those provided by local government that focused on policy issues. The most positive responses related to workshops taught by practicing teachers, workshops that sometimes covered areas that appear to have been neglected in pre-service training.

text: Teachers of English in Taiwanese primary schools reflect on their in-service training We report here on the responses of a sample of ten teachers in primary/ elementary schools in Taiwan to that part of a survey (based on a written questionnaire and semi-structured interview) that related to their experiences of in-service training provision in the teaching of English. Most of the in-service training that this sample of teachers had been exposed to was in the form of one-off workshops (offered by textbook publishers, local government and cram schools). Responses to these workshops were mixed. The most negative responses related to workshops provided by publishers and those provided by local government that focused on policy issues. The most positive responses related to workshops taught by practicing teachers, workshops that sometimes covered areas that appear to have been neglected in pre-service training.

year: 2008

title: Microsoft Translator Hub for Māori language

authors: Keegan, Te Taka Adrian Gregory

subjects: computer science

abstract: Recent improvements in Machine Translation (MT) software has opened new possibilities for applications of automatic language translation. But can these opportunities exist for the smaller, minority languages of the world? Training data was collected for the language pair of Māori and English which was used to build an MT system using Microsoft’s Translator Hub software. A comparative analysis was undertaken with this system and Google Translate. Various MT metrics and analysis software was considered before deciding to use the Asiya toolkit to undertake the comparative analysis. Māori language experts were also used to provide a human perspective on the output translations. The overall results showed no significant difference in the translation quality produced by the two systems. Despite some misgivings around the accuracy of the translations these results do show promise for MT usage by minority languages.

text: Microsoft Translator Hub for Māori language Recent improvements in Machine Translation (MT) software has opened new possibilities for applications of automatic language translation. But can these opportunities exist for the smaller, minority languages of the world? Training data was collected for the language pair of Māori and English which was used to build an MT system using Microsoft’s Translator Hub software. A comparative analysis was undertaken with this system and Google Translate. Various MT metrics and analysis software was considered before deciding to use the Asiya toolkit to undertake the comparative analysis. Māori language experts were also used to provide a human perspective on the output translations. The overall results showed no significant difference in the translation quality produced by the two systems. Despite some misgivings around the accuracy of the translations these results do show promise for MT usage by minority languages.

year: 2018