title: Synthesis of Piano Stool Complexes Employing the Pentafluorophenyl-Substituted Diphosphine (C₆F₅)₂PCH₂P(C₆F₅)₂ and the Effect of Phosphine Modifiers on Hydrogen Transfer Catalysis

authors: Marr, Andrew C.

subjects: chemistry

abstract: Ruthenium, rhodium, and iridium piano stool complexes of the pentafluorophenyl-substituted diphosphine (C₆F₅)₂PCH₂P(C₆F₅)₂ (2) have been prepared and structurally characterized by single-crystal X-ray diffraction. The η⁵,κP-Cp−P tethered complex [{(η5,κP-C₅Me₄CH₂C₆F₄-2-P(C₆F₅)CH₂P(C₆F₅)₂}RhCl₂] (9), in which only one phosphorus is coordinated to the rhodium, was prepared by thermolysis of a slurry of [Cp*RhCl(μ-Cl)]₂ and 2 and was structurally characterized by single-crystal X-ray diffraction. The tethering occurs by intramolecular dehydrofluorinative coupling of the η⁵-pentamethylcyclopentadienyl ligand and κP,κP-coordinated 2. The geometric changes that occur on tethering force dissociation of one of the phosphorus atoms. The effects of introducing phosphine ligands to the coordination sphere of piano stool hydrogen transfer catalysts have been studied. The complexes of fluorinated phosphine complexes are found to transfer hydrogen at rates that compare favorably with leading catalysts, particularly when the phosphine and cyclopentadienyl functionalities are tethered. The highly chelating η⁵,κP,κL-Cp−PP complex [(η⁵,κP,κP-C₅Me₄CH₂-2-C₅F₃N-4-PPhCH₂CH₂PPh₂)RhCl]BF₄ (1) was found to outperform all other complexes tested. The mechanism of hydrogen transfer catalyzed by piano stool phosphine complexes is discussed with reference to the trends in activity observed.

text: Synthesis of Piano Stool Complexes Employing the Pentafluorophenyl-Substituted Diphosphine (C₆F₅)₂PCH₂P(C₆F₅)₂ and the Effect of Phosphine Modifiers on Hydrogen Transfer Catalysis Ruthenium, rhodium, and iridium piano stool complexes of the pentafluorophenyl-substituted diphosphine (C₆F₅)₂PCH₂P(C₆F₅)₂ (2) have been prepared and structurally characterized by single-crystal X-ray diffraction. The η⁵,κP-Cp−P tethered complex [{(η5,κP-C₅Me₄CH₂C₆F₄-2-P(C₆F₅)CH₂P(C₆F₅)₂}RhCl₂] (9), in which only one phosphorus is coordinated to the rhodium, was prepared by thermolysis of a slurry of [Cp*RhCl(μ-Cl)]₂ and 2 and was structurally characterized by single-crystal X-ray diffraction. The tethering occurs by intramolecular dehydrofluorinative coupling of the η⁵-pentamethylcyclopentadienyl ligand and κP,κP-coordinated 2. The geometric changes that occur on tethering force dissociation of one of the phosphorus atoms. The effects of introducing phosphine ligands to the coordination sphere of piano stool hydrogen transfer catalysts have been studied. The complexes of fluorinated phosphine complexes are found to transfer hydrogen at rates that compare favorably with leading catalysts, particularly when the phosphine and cyclopentadienyl functionalities are tethered. The highly chelating η⁵,κP,κL-Cp−PP complex [(η⁵,κP,κP-C₅Me₄CH₂-2-C₅F₃N-4-PPhCH₂CH₂PPh₂)RhCl]BF₄ (1) was found to outperform all other complexes tested. The mechanism of hydrogen transfer catalyzed by piano stool phosphine complexes is discussed with reference to the trends in activity observed.

year: 2007

title: Model-driven GUI & interaction design using emulation

authors: Hinze, Annika

subjects: computer science

abstract: This paper introduces a model-driven emulator for the interaction and GUI design of complex interacting systems. It allows systems that are engineered using formal methods and modelling to be tested with users before the final implementation. The user interface requirements are also specified in a formal model, which can be tested manually and automatically as required.

text: Model-driven GUI & interaction design using emulation This paper introduces a model-driven emulator for the interaction and GUI design of complex interacting systems. It allows systems that are engineered using formal methods and modelling to be tested with users before the final implementation. The user interface requirements are also specified in a formal model, which can be tested manually and automatically as required.

year: 2010

title: Hone Werahiko: the discoverer of gold at Te Aroha

authors: Hart, Philip

abstract: Originally Hone Kahukahu, when he was living at Ohinemutu in the 1860s he became known as Hone Werahiko, an Arawa name he retained for the rest of his life. His father, a member of Ngati Kahungungu, had been captured by Arawa; his mother was a Waikato. A widow living at Maketu chose him as her second husband because he was ‘a good looking fellow & understood English’. 
In the late 1860s and much of the 1870s, he prospected in Hauraki and even in the King Country, and worked underground in a Thames mine, the only Maori known to have done so. But in the early 1870s he gave up mining to be a pioneer publican and storekeeper at Ohinemutu, at Rotorua. He acquired land and property there, but after his wife died he returned to prospecting full-time. 
Werahiko’s first investigation of Te Aroha was in 1877, when he was ordered off by the local hapu. He returned in 1880 as the head of a prospecting party subsidized by the government. After finding gold, he was granted the Prospectors’ Claim and, in due course, a reward, and for a time supervised its development. Investing in other claims, he traded in shares. When his discovery turned out to be a duffer, he explored other parts of the mountain, first having high hopes for the Tui portion but then, after four months of exploring over winter with the support of three other Maori, he announced the discovery of his New Find at Waiorongomai. Once again he acquired partners, mostly Paheka, and traded in shares, and for some time supervised the opening up of his new find.
Later, he was invited to prospect the King Country, but this did not eventuate. His last involvement in mining was at Karangahake. Because of the hardships of his prospecting at Te Aroha, he died at an early age, leaving a young second wife. His memory lived on, amongst Pakeha miners in particular, because he had the rare distinction for a prospector of being regarded as totally honest, and he was admired for succeeding when so many others had failed.

[Note: Especially when he first came to public attention, many Pakeha struggled with Hone Werahiko’s name, which was recorded in a variety of incorrect forms, the worst example being Hoani Whaekareka.  Even the warden at first gave his name as Hone Wharekino.  Many Pakeha found it simpler to refer to him as ‘Johnny the Maori’.  In this paper, his name is given correctly throughout.]

text: Hone Werahiko: the discoverer of gold at Te Aroha Originally Hone Kahukahu, when he was living at Ohinemutu in the 1860s he became known as Hone Werahiko, an Arawa name he retained for the rest of his life. His father, a member of Ngati Kahungungu, had been captured by Arawa; his mother was a Waikato. A widow living at Maketu chose him as her second husband because he was ‘a good looking fellow & understood English’. 
In the late 1860s and much of the 1870s, he prospected in Hauraki and even in the King Country, and worked underground in a Thames mine, the only Maori known to have done so. But in the early 1870s he gave up mining to be a pioneer publican and storekeeper at Ohinemutu, at Rotorua. He acquired land and property there, but after his wife died he returned to prospecting full-time. 
Werahiko’s first investigation of Te Aroha was in 1877, when he was ordered off by the local hapu. He returned in 1880 as the head of a prospecting party subsidized by the government. After finding gold, he was granted the Prospectors’ Claim and, in due course, a reward, and for a time supervised its development. Investing in other claims, he traded in shares. When his discovery turned out to be a duffer, he explored other parts of the mountain, first having high hopes for the Tui portion but then, after four months of exploring over winter with the support of three other Maori, he announced the discovery of his New Find at Waiorongomai. Once again he acquired partners, mostly Paheka, and traded in shares, and for some time supervised the opening up of his new find.
Later, he was invited to prospect the King Country, but this did not eventuate. His last involvement in mining was at Karangahake. Because of the hardships of his prospecting at Te Aroha, he died at an early age, leaving a young second wife. His memory lived on, amongst Pakeha miners in particular, because he had the rare distinction for a prospector of being regarded as totally honest, and he was admired for succeeding when so many others had failed.

[Note: Especially when he first came to public attention, many Pakeha struggled with Hone Werahiko’s name, which was recorded in a variety of incorrect forms, the worst example being Hoani Whaekareka.  Even the warden at first gave his name as Hone Wharekino.  Many Pakeha found it simpler to refer to him as ‘Johnny the Maori’.  In this paper, his name is given correctly throughout.]

year: 2016