Novel polyoxometalates: Is antimony the new molybdenum?

Polyoxometalates based on Mo, W or V have been known for a long time and present a diverse range of structures, with the [XMo₁₂O₄₀]ⁿ⁻ Keggin ions (X = P, Si ,…) perhaps the best known.¹ They are still subject to intense research with >4000 papers published in the past five years. Following on from our study² of aryl arsonic acids RAsO₃H₂, which are straightforward molecular species based on four-coordinate As(V), we became interested in the corresponding antimony compounds. Although aryl stibonic acids of nominal formula RSbO₃H₂ have been known for over 100 years,³ their composition has remained uncertain, as they form only amorphous solids, have complicated titration behaviour and only limited solubility. The presumption has been that they are polymeric, based on 5- or 6-coordinate Sb with Sb-O-Sb linkages, though direct evidence is sparse.⁴ Recently, it has been shown by Beckman that if very bulky R groups are used, then relatively simple dimers such as (2,6-Mes₂C₆H₃Sb₂O₂(OH)₄(Mes=mesityl) can be isolated, but these represent a special case.

Arylstibonic acids [H₈(RSb)₁₂O₂₈]; precursors to organometallic isopolyoxostibonates [Na₂H₉(RSb)₁₂O₃₀]-, (R = aryl).

Electrospray ionisation mass spectrometry shows that arylstibonic acids, RSbO₃H₂, give rise to oxo-bridged clusters derived from [H₈(RSb)₁₂O₂₈] which act as inorganic crown ligands towards Na+ cations; structure determination of one derivative revealed a cage-like anion [Na₂H₉(p-O₂NC₆H₄Sb)₁₂O₃₀.4H₂O]-

Internet Resource Management and Pricing

Originally conceived and funded as a research project, the Internet has grown into a commercial, global and integrated service network. This has changed the nature of traffic on the Internet with the increasing use of things like video conferencing and time critical transactions. These forms of Internet usage place high demands on bandwidth. Added to this is the fact that the number of users is increasing at a dramatic rate and shows no signs of slowing. This is leading to a \u27tragedy of the commons\u27 where endemic congestion will reduce the value of the Internet to everyone. It also implies the introduction of some form of quality of service (QoS) to differentiate time critical traffic from less time critical traffic. Pricing usage has been shown to be effective in controlling congestion by promoting more effective resource allocation. To provide the necessary QoS, there is an argument that simply increasing the available bandwidth will achieve this, while at the same time maintaining the simple model of the current Internet. However, there is also an argument that a more complex model may be needed that provides various levels of QoS with an associated pricing scheme to manage usage of these levels of QoS. A major part of the debate on this subject surrounds the trade-off between efficiency, economics and complexity that exists in introducing QoS and pricing to the Internet. This document discusses some of these issues, presents some of the current proposals for pricing Internet usage and finally compares the presented pricing proposals

Strategic Decision-Making in High Velocity Environments: A Theory Revisited and a Test

[Excerpt] A decade ago, Eisenhardt (1989) proposed a model of strategic decision-making speed for firms facing high-velocity environments. This theory, while important at the time, has become even more relevant to the strategy-making bodies of firms in the entrepreneurial millennium. The model differed in important ways from much of the existing literature on decision-making speed (Frederickson and Mitchell, 1984; Janis, 1982; Mintzberg, et al., 1976; Nutt, 1976). Eisenhardt\u27s ideas were based on a series of inductive case studies of eight firms competing in the fast-paced micro-chip industry. As such, it was an important theory-building effort in a central area of strategy process, strategic decision-making. To date, however, there have been no attempts to comprehensively test the model with a larger sample of firms. The changes the economy is experiencing in this new millennium are astounding. In short, the hyper-competitive forces faced a decade ago by micro-chip makers have become pervasive throughout many of our top industries (D\u27Aveni, 1994; Grimm and Smith, 1997). Thus, the prescriptions of Eisenhardt\u27s model would appear to be critical for today\u27s firms as they seek entrepreneurial approaches to gaining competitive advantage. Top management teams (TMTs) capable of making rapid decisions can enable their firms to be the entrepreneurial first movers in their respective segments. To our knowledge, however, there has been only one attempt to replicate Eisenhardt\u27s preliminary findings. Judge and Miller (1991) tested a portion of the model on a small sample (n = 32) of firms in three industries. The research tested two of the five tactics mentioned by Eisenhardt, did not incorporate the intervening processes, and produced mixed results. Thus, there have been no successful attempts to test the entire model on a large cross-section of firms. This is due in part to the difficulty researchers face in gaining access to a large sample of top executives, especially those facing fast-paced environments. This research tests Eisenhardt\u27s model on a sample of 66 high technology firms competing in the IT, telecommunications, and engineering services industries