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

‘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

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

Effect of empennage arrangement on single-engine nozzle/afterbody static pressures at transonic speeds

An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects on empennage arrangement on single-engine nozzle/afterbody static pressures. Tests were done at Mach numbers from 0.60 to 1.20, nozzle pressure ratios from 1.0 (jet off) to 8.0. and angles of attack from -3 to 9 deg (at jet off conditions), depending on Mach number. Three empennage arrangements (aft, staggered, and forward) were investigated. Extensive measurements were made of static pressure on the nozzle/afterbody in the vicinity of the tail surfaces

Coordination polymers and isomerism; a study using silver(I) and a ∏-stacked ligand

The ligand 2,5-bis(2-pyridylmethylsulfanylmethyl)pyrazine (L) was prepared by the base coupling of 2-(sulfanylmethyl)pyridine and 2,5-bis(chloromethyl)pyrazine. This new ligand was treated with AgClO₄ in a 1 1 metal-to-ligand ratio and with AgNO₃in a 2 1 metal-to-ligand ratio to give coordination polymers. The crystal structures of {[Ag(L)]ClO₄}∞ ( 1) and {[Ag₂(L)](NO₃)₂}∞ ( 2) were determined. The Ag(I) ions in the one-dimensional polymeric chains of 1 adopted square-pyramidal geometries with the pyridine and pyrazine N donors coordinated in an extremely bent fashion. The structure of 2 revealed two isomeric polymer chains in the one crystal forming a single supramolecular array. The isomeric polymers differed in the donor atoms about the Ag(I) ions and in the arrangement of adjacent ligands along the chain. A feature of both structures was that L adopted a three-layer ∏-stacked arrangement

Coordination chemistry of 3- and 4-mercaptobenzoate ligands: Versatile hydrogen-bonding isomers of the thiosalicylate (2-mercaptobenzoate) ligand

This review summarises the coordination chemistry of the isomeric 3- and 4-mercaptobenzoate ligands, derived from HSC6H4COOH, being isomers of the widely-studied 2-mercaptobenzoate (thiosalicylate) ligand. The 3- and 4-mercaptobenzoate ligands show a wide range of coordination modes, including monodentate (through either S or less commonly O), chelation through the carboxylate group alone, as well as a wide range of bridging modes. However, S,O-chelation, which is prevalent for thiosalicylate complexes, is not found in the 3MBA and 4MBA isomers. In the solid-state, complexes of 3MBA and 4MBA ligands containing protonated carboxylic acid groups typically undergo aggregation through formation of classical hydrogen-bonded carboxylic acid dimer motifs, which can be supplemented by additional interactions such as aurophilic (Au� � �Au) interactions in the case of gold(I) complexes. The hybrid hard-soft nature of 3MBA and 4MBA ligands facilitates the use of these ligands in the construction of early-late heterobimetallic complexes. These ligands also find numerous applications (such as the protection of metallic gold and silver nanoparticles), which are especially prevalent for 4MBA where the para carboxylate/carboxylic acid group is remote from the sulfur coordination site

Clinical review: Guyton - the role of mean circulatory filling pressure and right atrial pressure in controlling cardiac output

Arthur Guyton's concepts of the determinative role of right heart filling in cardiac output continue to be controversial. This paper reviews his seminal experiments in detail and clarifies the often confusing concepts underpinning his model. One primary criticism of Guyton's model is that the parameters describing venous return had not been measured in a functioning cardiovascular system in humans. Thus, concerns have been expressed in regard to the ability of Guyton's simplistic model, with few parameters, to model the complex human circulation. Further concerns have been raised in regard to the artificial experimental preparations that Guyton used. Recently reported measurements in humans support Guyton's theoretical and animal work

In Vitro Demonstration of Delayed Hypersensitivity in Patients with Berylliosis

To clarify immunopathological mechanisms in granulomatous hypersensitivity (GHR) to beryllium (Be), migration inhibitory factor (MIF) was assayed. Blood lymphocytes from three patients with GHR to Be and two normal persons were isolated and cultured with and without BeO or other antigens. Cell-free supernatants removed daily were dialyzed, lyophilized and assayed for MIF by measuring the area of migration of normal guinea pig peritoneal exudate cells out of capillary tubes within 24 hours after exposure to the supernatant. BeO added to sensitized lymphocytes produced supernatant that decreased migration, in contrast to supernatant from non-sensitized lymphocytes, indicating that BeO-sensitized lymphocytes cultured with Be elaborate a soluble factor, MIF, which correlates with delayed hypersensitivity and may play a role in granuloma formation. It may also prove useful in diagnosis of berylliosis