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Professor Xuechen Li was awarded the Rao Makineni Lectureship (2019) by American Peptide Society

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Professor Vivian Wing-Wah Yam (middle) and her research team

HKU chemists develop a new class of robust gold(III) complexes with promising device lifetimes and tunable emission colours for vacuum-deposited OLEDs

A team of researchers led by Professor Vivian Wing-Wah Yam, Philip Wong Wilson Wong Professor in Chemistry and Energy and Chair Professor of the Department of Chemistry, has overcome the key synthetic challenges for the design of robust gold(III) complexes and demonstrated for the first time highly efficient gold(III)-based organic light-emitting devices (OLEDs) with long operational lifetimes, reaching half-lifetimes of up to 83,000 hours. The findings have been published in January in the leading scientific journal, Nature Photonics (link).   Gold, a noble metal that has been widely used as currency and ornamental jewellery since ancient times and more recently in industry, has been a metal well-known for its inertness, low toxicity, and environmentally friendly and benign nature. With China having the second largest gold reserve in the world, there is a strong motivation and advantage of developing the organometallic chemistry and novel materials of gold, such as phosphorescent emitters for OLEDs. Through dedicated efforts and rational design of pincer and ancillary ligands, the team has found the right balance for the ligand coordination environment to overcome the thermal stability challenge, generating a new class of robust gold(III) complexes with tridentate C^C^N ligands. This class of gold(III) complexes demonstrates full-colour gamut spanning across the visible region from sky-blue to red with high solid-state photoluminescence quantum yields of up to 80%. These complexes are also capable of serving as phosphorescent dopants for OLEDs; notably, extraordinarily high current efficiencies of up to 72 cd A-1 and external quantum efficiencies of up to 21.6% have been achieved. More importantly, long device half-lifetimes of up to 83,000 hours have been realised in these gold(III)-based OLEDs. This is the first practical gold(III)-based OLEDs with long device lifetime. The present work holds great promise and would open up a new avenue for the development of new classes of practical phosphorescent emitters based on metal centres other than the commercially used but rare iridium(III) system, paving the way towards the possible revolutionisation of the OLED market.    More information about Professor Vivian Yam.

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HKU Vice-President and Chemistry scholar Professor Andy Hor  elected Fellow of the European Academy of Sciences

HKU Vice-President and Chemistry scholar Professor Andy Hor elected Fellow of the European Academy of Sciences

Professor Andy Hor, Vice President (Research) and Chair Professor of Metallic Chemistry & Materials at the University of Hong Kong (HKU), has been elected a fellow of the European Academy of Sciences (EurASc). EurASc is a non-profit, non-governmental and independent organisation established in 2003 in Brussels, aiming to promote excellence in science and technology. It awards prestigious prizes including the Leonardo da Vinci Award and the Blaise Pascal Medal. It currently has about 600 fellows, over 10% of whom are Nobel Laureate and Fields Medalists from over 40 countries. Professor Hor is honoured for his achievements and contributions to academia in the area of structural metallic chemistry. He specialises in the design, synthesis and structural analysis of novel molecules. His research lies at the fundamental of molecular science – to analyse the molecular composition and structure as a means to understand the properties and activities of a molecule or molecular materials, and from such knowledge, design new molecules, as well as develop new functions and applications. “This is how new science can be developed, translated and eventually be applied as new technologies,” said Professor Hor, who is honoured and delighted to receive the award. Professor Hor refers to the simple doctrine which has guided his research – technology is most disruptive when its science is at its (creative) root and said: “This is also how international fellowship like that from the European Academy of Science and prestigious prizes like Nobel Prize and Fields medal are conferred.” Over the years, his team has investigated a range of systems in coordination and organometallic complexes, hetero- and polynuclear aggregates and clusters, as well as metal-organic frameworks and molecular materials. These are molecular substances that form the basis of industrial chemicals, pharmaceutical catalysis as well as a range of energy and environmental applications. Recently, he has teamed up with scientists at the Agency of Science, Technology & Research (A*Star) of Singapore to study metal-air and metal-sulfide batteries as the next-generation of green batteries. Professor Hor has published over 435 international papers with an average of 1,200 annual citations in 2017-8, filed several patents in battery materials and supervised over 100 PhD, MSc and other research students. Biography of Professor Andy Hor Professor Andy Hor is the Vice President and Pro-Vice-Chancellor (Research) and Chair Professor of Metallic Chemistry & Materials of the University of Hong Kong (HKU). He started his academic career at the National University of Singapore (NUS) in which he also served as Head of Chemistry and Vice Dean (Academic) of Science. He later served as the Executive Director of the Institute of Materials Research & Engineering of the Agency of Science, Technology & Research (A*Star) of Singapore for 5 years before joining HKU in September 2015. He is Fellow of the Singapore National of Chemistry, Singapore National Academy of Science, and Royal Society of Chemistry in the UK, and former President of the Singapore National Institute of Chemistry and Federation of Asian Chemical Societies. He has contributed significantly over four decades to the development of chemistry in Singapore, Asia and the world through his research programs and various community services and leadership in international conferences and academic journals, and won numerous teaching and research awards while in NUS and A*Star. For Professor Hor’s detailed biography, please visit: https://presidentoffice.hku.hk/smt/pvc-R.html. EurASc website: http://www.eurasc.org/  

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Professor Xuechen Li was awarded the Rao Makineni Lectureship (2019) by American Peptide Society

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香港大學黃乾亨黃乾利基金教授(化學與能源)及化學系講座教授任詠華教授(中間)及其研究團隊

港大化學學者成功研發新一類穩健金(III)配合物 展示其蒸鍍型有機發光二極管具有長壽命和可調發光顏色特性

香港大學化學系任詠華教授領導的研究團隊成功克服了設計穩健金(III)配合物的關鍵合成難題,並首次展示高效、長壽的金(III)有機發光二極管,其器件壽命半衰期可達83,000小時。任教授團隊的研究成果剛於1月在國際頂尖科學期刊《自然—光子學》(Nature Photonics) 中發表 (連結))。   黃金是一種貴族金屬,自古以來就被廣泛應用於貨幣和裝飾珠寶,最近更在工業中被廣泛使用,以其惰性、低毒性、環保和良性特性而聞名。隨著中國擁有世界第二大黃金儲備,我們擁有強大的動力和優勢去開發金的有機金屬化學和含金新材料(如有機發光二極管的磷光發光材料)。通過不斷的研究努力和理性的鉗子和輔助配體結構設計,任教授團隊已經找到了配體配位環境的最佳平衡,克服了熱穩定性難題,創造出新一類含三齒C^C^N配體的金(III)配合物。這系列的金(III)配合物展示出可跨越整個可見光譜的全色色域,從天藍色到紅色,其固態光致發光量子產率更高達80%。這系列金(III)配合物亦能夠用作有機發光器件的磷光摻雜劑,器件的電流效率和外部量子效率高達72 cd/A 和 21.6%,壽命半衰期更長達83,000小時。這是首次展示長壽的金(III)有機發光二極管。這研究成果將為開發新型金屬磷光發光材料開闢一條新的途徑,不需依賴現時市面上使用的稀有的銥(III)體系,將為有機發光二極管市場打造革命性的改變。

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Professor Vivian Wing-Wah Yam (middle) and her research team

HKU chemists develop a new class of robust gold(III) complexes with promising device lifetimes and tunable emission colours for vacuum-deposited OLEDs

A team of researchers led by Professor Vivian Wing-Wah Yam, Philip Wong Wilson Wong Professor in Chemistry and Energy and Chair Professor of the Department of Chemistry, has overcome the key synthetic challenges for the design of robust gold(III) complexes and demonstrated for the first time highly efficient gold(III)-based organic light-emitting devices (OLEDs) with long operational lifetimes, reaching half-lifetimes of up to 83,000 hours. The findings have been published in January in the leading scientific journal, Nature Photonics (link).   Gold, a noble metal that has been widely used as currency and ornamental jewellery since ancient times and more recently in industry, has been a metal well-known for its inertness, low toxicity, and environmentally friendly and benign nature. With China having the second largest gold reserve in the world, there is a strong motivation and advantage of developing the organometallic chemistry and novel materials of gold, such as phosphorescent emitters for OLEDs. Through dedicated efforts and rational design of pincer and ancillary ligands, the team has found the right balance for the ligand coordination environment to overcome the thermal stability challenge, generating a new class of robust gold(III) complexes with tridentate C^C^N ligands. This class of gold(III) complexes demonstrates full-colour gamut spanning across the visible region from sky-blue to red with high solid-state photoluminescence quantum yields of up to 80%. These complexes are also capable of serving as phosphorescent dopants for OLEDs; notably, extraordinarily high current efficiencies of up to 72 cd A-1 and external quantum efficiencies of up to 21.6% have been achieved. More importantly, long device half-lifetimes of up to 83,000 hours have been realised in these gold(III)-based OLEDs. This is the first practical gold(III)-based OLEDs with long device lifetime. The present work holds great promise and would open up a new avenue for the development of new classes of practical phosphorescent emitters based on metal centres other than the commercially used but rare iridium(III) system, paving the way towards the possible revolutionisation of the OLED market.    More information about Professor Vivian Yam.

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HKU Vice-President and Chemistry scholar Professor Andy Hor  elected Fellow of the European Academy of Sciences

HKU Vice-President and Chemistry scholar Professor Andy Hor elected Fellow of the European Academy of Sciences

Professor Andy Hor, Vice President (Research) and Chair Professor of Metallic Chemistry & Materials at the University of Hong Kong (HKU), has been elected a fellow of the European Academy of Sciences (EurASc). EurASc is a non-profit, non-governmental and independent organisation established in 2003 in Brussels, aiming to promote excellence in science and technology. It awards prestigious prizes including the Leonardo da Vinci Award and the Blaise Pascal Medal. It currently has about 600 fellows, over 10% of whom are Nobel Laureate and Fields Medalists from over 40 countries. Professor Hor is honoured for his achievements and contributions to academia in the area of structural metallic chemistry. He specialises in the design, synthesis and structural analysis of novel molecules. His research lies at the fundamental of molecular science – to analyse the molecular composition and structure as a means to understand the properties and activities of a molecule or molecular materials, and from such knowledge, design new molecules, as well as develop new functions and applications. “This is how new science can be developed, translated and eventually be applied as new technologies,” said Professor Hor, who is honoured and delighted to receive the award. Professor Hor refers to the simple doctrine which has guided his research – technology is most disruptive when its science is at its (creative) root and said: “This is also how international fellowship like that from the European Academy of Science and prestigious prizes like Nobel Prize and Fields medal are conferred.” Over the years, his team has investigated a range of systems in coordination and organometallic complexes, hetero- and polynuclear aggregates and clusters, as well as metal-organic frameworks and molecular materials. These are molecular substances that form the basis of industrial chemicals, pharmaceutical catalysis as well as a range of energy and environmental applications. Recently, he has teamed up with scientists at the Agency of Science, Technology & Research (A*Star) of Singapore to study metal-air and metal-sulfide batteries as the next-generation of green batteries. Professor Hor has published over 435 international papers with an average of 1,200 annual citations in 2017-8, filed several patents in battery materials and supervised over 100 PhD, MSc and other research students. Biography of Professor Andy Hor Professor Andy Hor is the Vice President and Pro-Vice-Chancellor (Research) and Chair Professor of Metallic Chemistry & Materials of the University of Hong Kong (HKU). He started his academic career at the National University of Singapore (NUS) in which he also served as Head of Chemistry and Vice Dean (Academic) of Science. He later served as the Executive Director of the Institute of Materials Research & Engineering of the Agency of Science, Technology & Research (A*Star) of Singapore for 5 years before joining HKU in September 2015. He is Fellow of the Singapore National of Chemistry, Singapore National Academy of Science, and Royal Society of Chemistry in the UK, and former President of the Singapore National Institute of Chemistry and Federation of Asian Chemical Societies. He has contributed significantly over four decades to the development of chemistry in Singapore, Asia and the world through his research programs and various community services and leadership in international conferences and academic journals, and won numerous teaching and research awards while in NUS and A*Star. For Professor Hor’s detailed biography, please visit: https://presidentoffice.hku.hk/smt/pvc-R.html. EurASc website: http://www.eurasc.org/  

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Professor Chi-ming Che introducing the department to Mr Yang

The Secretary for Innovation and Technology Mr Nicholas Yang visited Department of Chemistry

The Secretary for Innovation and Technology Mr Nicholas Yang visited Department of Chemistry on Dec 21, 2018. Head of Department and Zhou Guangzhao Professorship in Natural Sciences, Professor Chi-ming Che, firstly introduced the distinguished achievements of the department including ongoing frontier research projects, advanced collaborative projects with industry and international recognitions of their researchers. Professor Che then delineated the future development plans with creating strong impacts to the society as the focus to Mr Yang.   Followed by Professor Che’s introduction, researchers at the department introduced Area of Excellence Programmes, State Key Laboratory and frontier research projects in diverse areas to Mr Yang. Professor Che concluded the meeting by emphasising that the department would continuously strive for excellence in scientific research. He hoped that Innovation and Technology Bureau would continuously devote resources in facilitating scientific research.   Group photos of researchers of Department of Chemistry and Mr Nicholas Yang (fifth from the left).   Professor Vivian Wing-Wah YAM, Chair Professor and Philip Wong Wilson Wong Professor in Chemistry and Energy, introducing her frontier research.    

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The Play&Grow programme connects preschool children to nature

Connection of children to nature brings less distress, hyperactivity and behavioural problems – now measurable with a novel scale developed by HKU scientist

City lifestyle has been criticised for being an important reason for children being disconnected from nature. This has led to an unhealthy lifestyle in regards to active play and eating habits. Even worse, many young children do not feel well psychologically – they are often stressed and depressed. 16 per cent of pre-schoolers in Hong Kong and up to 22% in China show signs of mental health problems (Kwok SY, Gu M, Cheung AP, 2017; Zhu J, et al. 2017).   Recent research shows that spending time in nature may bring many health benefits, and many environmental programmes around the world are trying to decrease ‘nature-deficit’ and ‘child-nature disconnectedness’ in order to improve children’s health. For example, the WHO, in order to monitor implementation of the Parma Declaration commitment to providing every child with access to “green spaces to play and undertake physical activity”, has set a 300-meter target. Interestingly, 90 per cent of the Hong Kong population lives within 400 metres of such areas. However, despite the extensive, adjacent greenness, families are not using these areas.   “We noticed a tendency where parents are avoiding nature. They perceive it as dirty and dangerous, and their children unfortunately pick up these attitudes. In addition, the green areas are often unwelcoming with signs like “Keep off the grass”, said Dr Tanja Sobko from the School of Biological Sciences. Until now, it has not been possible to measure connectedness to nature in preschool children, mostly due to the fact that they are too young to answer for themselves.   A new 16-item parent questionnaire (CNI-PPC) to measure “connectedness to nature’ in very young children has been developed by Dr Sobko and her collaborator Professor Gavin Brown, Director of the Quantitative Data Analysis and Research Unit at the University of Auckland. The questionnaire identified four areas that reflect the child-nature relationship: enjoyment of nature, empathy for nature, responsibility towards nature, and awareness of nature.   The study consisted of two parts: the initial interviews with the families and the subsequent development of the questionnaire. Altogether, 493 families with children aged between 2 and 5 have participated in the study. Finally the new questionnaire was tested against the Strengths and Difficulties Questionnaire, a well-established measurement of psychological well-being and children’s behaviour problems. The results revealed that parents who saw their child had a closer connection with nature had less distress, less hyperactivity, & fewer behavioural and emotional difficulties, and improved pro-social behaviour. Interestingly, children who took greater responsibility towards the nature had fewer peer difficulties. The results give a new possibility for investigating the link between the outdoor environment and well-being in pre-school children.   The study is part of Dr Sobko’s research-based programme Play&Grow, which is the first in Hong Kong to promote healthy eating and active playtime with preschool children by connecting them to nature. Launched 2016, it has so far included almost 1000 families from all over Hong Kong. (https://foodnaturelab.org/page).   The findings have been published in multidisciplinary Open Access journal, PLOS ONE. The new scale has already attracted international attention and is being adopted by universities worldwide including Western Australia and Deakin Universities. In addition, the HKU-developed ‘Play&Grow’ programme is also on track to be conducted in Australia.   The next step is to further fine-tune future health promotion/disease prevention interventions, which Dr Sobko and the team are committed to. “We are grateful for the recognition of the Government, which has recently granted significant financial support to this important project”, said Dr Sobko. The new exciting extension of this work is to test the effect of the exposing children to nature and changes in their gut microbiota.   To view the journal paper "Connectedness to Nature Index - Parents of Preschool Children PlosOne", please click here.           

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