Preservation and conservation decisions in the local library

For a period of years, I have been aware that the decisions regarding preservation which I have made, which I have shared in making, or which have been made by others have not all been of the same nature. The level or levels within the library's staff hierarchy of the persons involved make some decisions differ from other decisions; however, these levels of involvement are not the heart of the problem. The thing lacking was a clear way to designate other distinctions which seemed necessary in attempting to analyze such problems and decisions. I found little help in my reading or sharing experiences with others in attempting to work in this area. In reading the proceedings of the 1976 conference on A National Preservation Program at the Library of Congress, I was therefore quite interested to discover that Daniel Boorstin in opening the conference suggested a division of the questions comprising the problem of preservation. He characterized two rather distinct types of problems as epistemological and technical. He further described the epistemological questions as being social questions, meaning that they are questions relating to the interests of those who will use, administer, and service the materials comprising the collections. I must admit that the term epistemological sent me to the dictionary because it has been some time since I had studied formal philosophical language. At this point, it becomes necessary to understand Boorstin's exact meaning and intention in interjecting this term into the vocabulary of library preservation. Epistemology is defined as "the study of the methods and grounds of knowledge especially with reference to its limits and validity; broadly: the theory of knowledge."published or submitted for publicatio

New ferrocene-derived hydroxymethylphosphines: FcP(CH₂OH)₂ [Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄)] and the dppf analogue 1,1′-Fc′[P(CH₂OH)₂]₂ [Fc′=Fe(η⁵-C₅H₄)₂]

Reactions of the ferrocene-phosphines FcPH₂ and 1,1′-Fc′(PH₂)₂ with excess formaldehyde gives the new hydroxymethylphosphines FcP(CH₂OH)₂ 1 and 1,1′-Fc′[P(CH₂OH)₂]₂ 2, respectively. Phosphine 1 is an air-stable crystalline solid, whereas 2 is isolated as an oil. Reaction of 1 with H₂O₂, S₈ or Se gives the chalcogenide derivatives FcP(E)(CH₂OH)₂ (E=O, S or Se), whilst reaction of 2 with S8 gives 1,1′-Fc′[P(S)(CH₂OH)₂]₂, which were fully characterised. Phosphine 1 was also characterised by an X-ray crystal structure determination

Cycloaurated GoId (III) complexes- Possible alternatives to cisplatin?

The serendipitous discovery of the anti-tumour activity of cisplatin [cis-PtCI₂(NH₃)₂] in 1969 has led to increased interest in the development of new metal-based anti-cancer drugs. However, regardless of the large numbers of new metal-containing compounds generated, many of which demonstrate anti-tumour activity, cisplatin still remains one of the most widely used anti-tumour drugs in the western world

‘User-friendly’ primary phosphines and an arsine: synthesis and characterization of new air-stable ligands incorporating the ferrocenyl group

Reaction of FcCH₂CH₂P(O)(OH)₂ or FcCH₂P(O)(OH)(OEt) [Fc=Fe(η⁵-C₅H₄)(η⁵-C₅H₅)] with excess CH₂N₂ followed by reduction with Me₃SiCl–LiAlH₄ gives the air-stable primary phosphines FcCH₂CH₂PH₂ and the previously reported analogue FcCH₂PH₂ in high yields. Reduction of 1,1′-Fc′[CH₂P(O)(OEt)₂] [Fc′=Fe(η⁵-C₅H₄)₂] and 1,2-Fc″[CH₂P(O)(OEt)₂] [Fc″=Fe(η⁵-C₅H₅)(η⁵-C₅H₃)] similarly gives the new primary phosphines 1,1′-Fc′(CH₂PH₂)₂ and 1,2-Fc″(CH₂PH₂)₂, respectively. The arsine FcCH₂CH₂AsH₂, which is also air-stable, has been prepared by reduction of the arsonic acid FcCH₂CH₂As(O)(OH)₂ using Zn/HCl. An X-ray structure has been carried out on the arsine, which is only the second structure determination of a free primary arsine. The molybdenum carbonyl complex [1,2-Fc″(CH₂PH₂)₂Mo(CO)₄] was prepared by reaction of the phosphine with [Mo(CO)₄(pip)₂] (pip=piperidine), and characterized by a preliminary X-ray structure determination. However, the same reaction of 1,1′-Fc′(CH₂PH₂)₂with [Mo(CO)₄(pip)₂] gave [1,1′-Fc′(CH₂PH₂)₂Mo(CO)₄] and the dimer [1,1′-Fc′(CH₂PH₂)₂Mo(CO)₄]₂, characterized by electrospray mass spectrometry. 1,1′-Fc′[CH₂PH₂Mo(CO)₅]₂ and 1,2-Fc″[CH₂PH₂Mo(CO)₅]₂ were likewise prepared from the phosphines and excess [Mo(CO)₅(THF)]

Ferrocenyl hydroxymethylphosphines (η⁵-C₅H₅)Fe[η⁵⁻C₅H₄P(CH₂OH)₂] and 1,1′-[Fe{η⁵-C₅H₄P(CH₂OH)₂}₂] and their chalcogenide derivatives

The ferrocenyl hydroxymethylphosphines FcP(CH₂OH)₂ [Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄)] and 1,1′-Fc′[P(CH₂OH)₂]₂ [Fc′=Fe(η⁵⁻C₅H₄)₂] were prepared by reactions of the corresponding primary phosphines FcPH₂ and 1,1′-Fc′(PH₂)₂ with excess aqueous formaldehyde. The crystal structure of FcP(CH₂OH)₂ was determined and compared with the known ferrocenyl hydroxymethylphosphine FcCH₂P(CH₂OH)₂. The chalcogenide derivatives FcP(E)(CH₂OH)₂ and 1,1′-Fc′[P(E)(CH₂OH)₂]₂ (E=O, S, Se) were prepared and fully characterised. Crystal structure determinations on FcP(O)(CH₂OH)₂ and FcP(S)(CH₂OH)₂ were performed, and the hydrogen-bonding patterns are compared with related compounds. The sulfide shows no hydrogen-bonding involving the phosphine sulfide group, in contrast to other reported ferrocenyl hydroxymethylphosphine sulfides. The platinum complex cis-[PtCl₂{FcP(CH₂OH)₂}₂] was prepared by reaction of 2 mol equivalents of FcP(CH₂OH)₂ with [PtCl₂(1,5-cyclo-octadiene)], and was characterised by 31P-NMR spectroscopy and negative ion electrospray mass spectrometry, which gave a strong [M+Cl]⁻ ion

Platinum(II) complexes containing ferrocene-derived phosphonate ligands; synthesis, structural characterisation and antitumour activity

Platinum ferrocenyl–phosphonate complexes, containing four-membered Pt---O---P(O)---O rings, have been synthesised by the reactions of cis-[PtCl₂(PPh₃)₂] with the ferrocene-derived phosphonic acids Fc(CH₂)nP(O)(OH)₂(n=0–2) [Fc=(η⁵-C₅H₄)Fe(η⁵-C₅H₅)] and 1,1′-Fc′[P(O)(OH)₂]₂ [Fc′=Fe(η⁵-C₅H₄)₂] in the presence of Ag₂O. The complexes have been characterised by NMR spectroscopy, together with crystal structure determinations on [Fc(CH₂)nPO₃Pt(PPh₃)₂] (n=1, 2) and [1,1′-Fc′{PO₃Pt(PPh₃)₂}₂]. The complexes [Fc(CH₂)nPO₃Pt(PPh₃)₂] (n=1, 2) show moderate activity against P388 leukaemia cells, whereas the parent phosphonic acids are inactive

Platinum(II), palladium(II) and gold(III) complexes containing 1,1,4-trisubstituted thiosemicarbazide dianion ligands

Reactions of cis-[PtCl₂(PPh₃)₂] or [PdCl₂(PPh₃)₂] with Ph₂N---NHC(S)NHPh and excess triethylamine, in refluxing methanol gave the complexes [M{SC(=NPh)NNPh₂}(PPh₃)₂] containing thiosemicarbazide dianion ligands. An analogous gold(III) complex containing the cyclo-aurated anilinopyridine ligand was also synthesised. A single crystal X-ray diffraction study was carried out on the complex [Pt{SC(=NPh)NNPh₂}(PPh₃)₂] which confirmed the bonding of the thiosemicarbazide dianion ligand via sulfur and the nitrogen bearing the NPh₂ substituent. In contrast, reaction of Ph₂N---NHC(S)NHMe with cis-[PtCl₂(PPh₃)₂] and excess triethylamine gave the complex [Pt{SC(=NNPh₂)NMe}(PPh₃)₂], containing a Pt---NMe group, characterized spectroscopically

Synthesis and characterisation of ferrocenyl-phosphonic and -arsonic

The ferrocene-derived acids FcCH₂CH₂E(O)(OH)₂ [4, E=P; 10, E=As; Fc=Fe(η₅-C₅H₅)(η⁵-C₅H₄)] have been synthesized by the reaction of FcCH₂CH₂Br with either P(OEt)₃ followed by hydrolysis, or with sodium arsenite followed by acidification. Reaction of FcCH₂OH with (EtO)₂P(O)Na gave FcP(O)(OEt)(OH), which was converted to FcCH₂P(O)(OH)₂ (3) by silyl ester hydrolysis using Me₃SiBr–Et₃N followed by aqueous work-up. Similarly, the known phosphonic acid FcP(O)(OH)₂and the new derivatives 1,1′-Fc′[P(O)(OH)₂]₂ [Fc′=Fe(η⁵-C₅H₄)₂] and 1,1′-Fc′[CH₂P(O)(OH)₂]₂(7) have been synthesized via their corresponding esters. X-ray crystal structure determinations have been carried out on 3 and 7, and the hydrogen-bonding networks discussed. Electrospray mass spectrometry has been employed in the characterization of the various acids. Phosphonic acids give the expected [M–H]− ions and their fragmentation at elevated cone voltages has been found to be dependent on the acid. FcP(O)(OH)₂ fragments to [C₅H₄PO₂H]−, but in contrast Fc(CH₂)nP(O)(OH)₂ (n=1, 2) give Fe{η⁵-C₅H₄(CH₂)nP(O)O₂]− ions, which are proposed to have an intramolecular interaction between the Fe atom and the phosphonate group. In contrast, arsonic acid (10), together with PhAs(O)(OH)₂for comparison, undergo facile alkylation (in methanol or ethanol solvent), and at elevated cone voltages (e.g. >60 V) undergo carbon–arsenic bond cleavage giving [CpFeAs(O)(OR)O]− (R=H, Me, Et) and ultimately [AsO₂]− ions

On the experimental testing of fine Nitinol wires for medical devices

Nitinol, a nickel titanium alloy, is widely used as a biocompatible metal with applications in high strain medical devices. The alloy exhibits both superelasticity and thermal shape memory behaviour. Basic mechanical properties can be established and are provided by suppliers; however the true stress–strain response under repeated load is not fully understood. It is essential to know this behaviour in order to design devices where failure by fatigue may be possible. The present work develops an approach for characterising the time varying mechanical properties of fine Nitinol wire and investigates processing factors, asymmetric stress–strain behaviour, temperature dependency, strain rate dependency and the material response to thermal and repeated mechanical loading. Physically realistic and accurately determined mechanical properties are provided in a format suitable for use in finite element analysis for the design of medical devices. Guidance is also given as to the most appropriate experimental set up procedures for gripping and testing thin Nitinol wire