Alkali metal derivatives of an ortho-phenylene diamine

Treatment of the ortho-phenylene diamine C6H4-1,2-{N(H)Tripp}2 (1, PDAH2, Tripp = 2,4,6-triisopropylphenyl) with two equivalents of MR (M = Li, R = Bun; M = Na or K, R = CH2C6H5) afforded the dimetallated alkali metal ortho-phenylene diamide dianion complexes [(PDALi2)(THF)3] (2), [{(PDANa2)(THF)2}2] (3), and [{(PDAK2)(THF)3}2] (4). In contrast, treatment of 2 with two equivalents of rubidium or cesium 2-ethylhexoxide, or treatment of 1 with two equivalents of MR (M = Rb or Cs, R = CH2C6H5) did not afford the anticipated dialkali metal ortho-phenylene diamide dianion derivatives and instead formally afforded the monometallic ortho-diiminosemiquinonate radical anion species [PDAM] (M = Rb, 5; M = Cs, 6). The structure of 2 is monomeric with one lithium coordinated to the two nitrogen centres and the other lithium η4-coordinated to the diazabutadiene portion of the PDA scaffold. Similar structural cores are observed for 3 and 4, except that the larger sodium and potassium ions give dimeric structures linked by multi-hapto interactions from the PDA backbone phenyl ring to an alkali metal centre. Complex 5 was not characterised in the solid state, but the structure of 6 reveals coordination of cesium ions to both PDA amide centres and multi-hapto interactions to a PDA backbone phenyl ring in the next unit to generate a one-dimensional polymer. Complexes 2–6 have been variously characterised by X-ray crystallography, multi-nuclear NMR, FTIR, and EPR spectroscopies, and CHN microanalyses

Teachers' perception on teacher empowerment in Hong Kong aided secondary schools

published_or_final_versionEducationMasterMaster of Educatio

Assessing financial market integration in Asia - Equity markets

Financial integration has strong implications for financial stability. On the one hand, financial integration among economies helps to improve their capacity to absorb shocks and foster development. On the other hand, intensified financial linkages in a world of increasing capital mobility may also harbour the risk of cross-border financial contagion. This paper provides a survey of high-frequency indicators to monitor the development of equity market integration in Asia. The results show that after slowing down between 2002 and 2006, the equity market integration process picked up again in 2007-08. Nevertheless, the process is not complete and the degrees of integration between mature and emerging equity markets are different. The divergence may be attributed to the difference in the political, economic and institutional aspects across jurisdictions in Asia.Financial integration Cointegration Common component Synchronisation Dynamic correlation

Synthesis and Structural Characterization of Lithium, Potassium, Magnesium, and Heavier Group 14 Metal Complexes Derived from 2‑Quinolyl-Linked (Thiophosphorano)methane

The synthesis and structural characterization of lithium, magnesium, potassium, and a series of low-valent group 14 metal compounds derived from the novel 2-quinolyl-linked phosphoranosulfide CH₂(^<i>i</i>Pr₂PS)­(C₉H₆N-2) (<b>3</b>) are reported. The monoanionic thiophosphinoyl lithium complex [Li­(Et₂O)­{CH­(^<i>i</i>Pr₂P–S)­(C₉H₆N-2)}]₂ (<b>4</b>) and magnesium complex [Mg­{CH­(^<i>i</i>Pr₂P–S)­(C₉H₆N-2)}₂] (<b>5</b>) have been prepared from the reaction of <b>3</b> with 1 equiv of ^<i>n</i>BuLi or 0.5 equiv of ^<i>n</i>Bu₂Mg in THF. Metathesis of <b>4</b> with 2 equiv of K^<i>t</i>BuO afforded the corresponding polymeric thiophosphinoyl potassium complex [K­{CH­(^<i>i</i>Pr₂P–S)­(C₉H₆N-2)}]_<i>n</i> (<b>6</b>). The metathesis reaction of <b>4</b> with GeCl₂·(dioxane) and PbCl₂ afforded the “open-box” 1,3-digermacyclobutane [Ge­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>9</b>) and “twisted-step” 1,3-diplumbacyclobutane [Pb­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>10</b>), respectively. Reaction of <b>3</b> with 1 equiv of M­{N­(SiMe₃)₂}₂ (M = Sn, Pb) afforded the corresponding “open-box” 1,3-distannacyclobutane [Sn­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>11</b>) and [Pb­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>12</b>), respectively. The structures of <b>3</b>–<b>6</b> and <b>9</b>–<b>12</b> have been determined by X-ray crystallography

Synthesis and Structural Characterization of Lithium, Potassium, Magnesium, and Heavier Group 14 Metal Complexes Derived from 2‑Quinolyl-Linked (Thiophosphorano)methane

The synthesis and structural characterization of lithium, magnesium, potassium, and a series of low-valent group 14 metal compounds derived from the novel 2-quinolyl-linked phosphoranosulfide CH₂(^<i>i</i>Pr₂PS)­(C₉H₆N-2) (<b>3</b>) are reported. The monoanionic thiophosphinoyl lithium complex [Li­(Et₂O)­{CH­(^<i>i</i>Pr₂P–S)­(C₉H₆N-2)}]₂ (<b>4</b>) and magnesium complex [Mg­{CH­(^<i>i</i>Pr₂P–S)­(C₉H₆N-2)}₂] (<b>5</b>) have been prepared from the reaction of <b>3</b> with 1 equiv of ^<i>n</i>BuLi or 0.5 equiv of ^<i>n</i>Bu₂Mg in THF. Metathesis of <b>4</b> with 2 equiv of K^<i>t</i>BuO afforded the corresponding polymeric thiophosphinoyl potassium complex [K­{CH­(^<i>i</i>Pr₂P–S)­(C₉H₆N-2)}]_<i>n</i> (<b>6</b>). The metathesis reaction of <b>4</b> with GeCl₂·(dioxane) and PbCl₂ afforded the “open-box” 1,3-digermacyclobutane [Ge­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>9</b>) and “twisted-step” 1,3-diplumbacyclobutane [Pb­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>10</b>), respectively. Reaction of <b>3</b> with 1 equiv of M­{N­(SiMe₃)₂}₂ (M = Sn, Pb) afforded the corresponding “open-box” 1,3-distannacyclobutane [Sn­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>11</b>) and [Pb­{μ₂-C­(^<i>i</i>Pr₂PS)­(C₉H₆N-2)]₂ (<b>12</b>), respectively. The structures of <b>3</b>–<b>6</b> and <b>9</b>–<b>12</b> have been determined by X-ray crystallography

Synthesis and Structural Characterization of a Tin Analogue of Allene

The reaction of [MgC­(PPh₂S)₂(THF)]₂ (<b>1</b>; THF = tetrahydrofuran) with 1 equiv of SnCl₄ in THF afforded a novel tin analogue of allene [Sn­{C­(PPh₂S)₂}₂] (<b>2</b>). The structure of compound <b>2</b> has been characterized by X-ray crystallography and NMR spectroscopy