Convenient synthetic routes to bidentate and monodentate 2-, 3- and 4-pyridyl phosphines: potentially useful ligands for water-soluble complex catalysts

The monodentate and bidentate pyridyl phosphines, PR3 and R2P(CH2)2PR2, where R=3- or 4-pyridyl can be prepared in high yields by treatment of butyllithium/TMEDA/3- or 4-bromopyridine with PCl3 or Cl2P(CH2)2PCl2 at low temperature. 1,2-Bis(di-2-pyridylphosphino)ethane is conveniently synthesised by an alternative route involving reaction of 1,2-dibromoethane with lithium di-2-pyridylphosphide.

Twentieth Century Society Spring lecture series: second lives for Twentieth Century masterpieces

The Twentieth Century Society’s Spring lecture series (six in total) looks at the restoration and refurbishment of key C20 buildings in Britain and the US. Buildings covered: BBC Broadcasting House in London (G Val Meyer 1930-32, MacCormac Jamieson Prichard 2000-09). Speaker: Mark Hines (Mark Hines Architects), was the project architect and is the author of The Story of Broadcasting House: Home of the BBC. 5 February 2009. Crown Hall, Chicago (Mies van der Rohe 1952), the Art and Architecture Building, Yale University, New Haven (Paul Rudolf 1961-63) and the former Wills head office in Bristol (SOM with YRM 1970-75). Speaker: Patrick Bellew (Atelier 10 Engineers), 12 February 2009. Center for British Art, Yale University, New Haven (Louis Kahn 1969-77). Speaker: Peter Inskip (Inskip and Jenkins Architects), 17 February 2009. Brunswick Centre London (Patrick Hodgkinson 1967-72; Levitt Bernstein with Patrick Hodgkinson 2006). Speaker: Stuart Tappin (Stand Consulting Engineers Ltd), 26 February 2009. De La Warr Pavilion, Bexhill-on-Sea (Mendelsohn and Chermayeff 1934-5, John McAslan and Partners 2000-05). Speaker: Mark Cannata (HOK Architects), 5 March 2009. Finsbury Health Centre London (Lubetkin & Tecton 1938, first phase of conservation work Avanti Architects 1995.). Speaker: John Allan of Avanti Architects, 12 March 2009.

Prehistoric Pinus woodland dynamics in an upland landscape in northern Scotland: the roles of climate change and human impact

Pollen, microscopic charcoal, palaeohydrological and dendrochronological analyses are applied to a radiocarbon and tephrochronologically dated mid Holocene (ca. 8500–3000 cal B.P.) peat sequence with abundant fossil Pinus (pine) wood. The Pinus populations on peat fluctuated considerably over the period in question. Colonisation by Pinus from ca. 7900–7600 cal B.P. appears to have had no specific environmental trigger; it was probably determined by the rate of migration from particular populations. The second phase, at ca. 5000–4400 cal B.P., was facilitated by anthropogenic interference that reduced competition from other trees. The pollen record shows two Pinus declines. The first at ca. 6200–5500 cal B.P. was caused by a series of rapid and frequent climatic shifts. The second, the so-called pine decline, was very gradual (ca. 4200–3300 cal B.P.) at Loch Farlary and may not have been related to climate change as is often supposed. Low intensity but sustained grazing pressures were more important. Throughout the mid Holocene, the frequency and intensity of burning in these open Pinus–Calluna woods were probably highly sensitive to hydrological (climatic) change. Axe marks on several trees are related to the mid to late Bronze Age, i.e., long after the trees had died.

Peat, pine stumps and people: interactions behind climate, vegetation change and human activity in wetland archaeology at Loch Farlary, Northern Scotland

First paragraph: In 1993, a peat-cutter, Bruce Field, working on the blanket peat bank he rented from the Sutherland Estate by Loch Farlary, above Golspie in Sutherland (fig 1), reported to Scottish Natural Heritage and Historic Scotland several pieces of pine wood bearing axe marks. Their depth in the peat suggested the cut marks to be prehistoric. This paper summarizes the work undertaken to understand the age and archaeological significance of this find (see also Tipping et al 2001 in press). The pine trees were initially thought to be part of a population that flourished briefly across northern Scotland in the middle of the Holocene period from c 4800 cal BP (Huntley, Daniell & Allen 1997). The subsequent collapse across northernmost Scotland of this population, the pine decline, at around 4200-4000 cal BP is unexplained: climate change has been widely assumed (Dubois & Ferguson 1985; Bridge, Haggart & Lowe 1990; Gear & Huntley 1991) but anthropogenic activity has not been disproved (Birks 1975; Bennett 1995). It was hypothesized that the Farlary find would allow for the first time the direct link between human woodland clearance and the Early Bronze Age pine decline.