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The crystal structures of a number of fungicidal azolylmethanes are compared. In the benzyl compounds [1-aryl-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-ones, the corresponding pentan-3-ols, and 1-(4-chlorophenyl)-3-(2-fluorophenyl)-2-(1,2,4-triazol-1-yl)propan-1-one], the benzyl and tert-butyl groups (or 4-chlorophenyl group) are trans, whereas in the analogous phenoxy compounds [1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)butan-2-one and the corresponding butan-2-ol], the tert-butyl groups are trans to the triazole and gauche to the phenoxy group. Coupling constants, determined by nuclear magnetic resonance (n.m.r.) spectroscopy, suggest that for some compounds there is one dominant solution conformation. Intramolecular hydrogen bonding, observed by infrared spectroscopy in two of the compounds, supports the findings by n.m.r. For some compounds, the crystal and solution conformations appear to be very similar, whereas in others they are quite different. Published data on the relative activity of the enantiomers of the benzyl- and phenoxy-compounds are discussed, but differences in the relative activity of enantiomers in the two series cannot be readily rationalised. It is concluded that different enantiomers may have different modes of binding at the active site.

10-Phenylphenoxaphosphine (2) undergoes quaternization with phenacyl bromide in nitromethane five times more slowly than triphenylphosphine and almost twenty times more slowly than o-methoxyphenyldiphenylphosphine. It is argued that stabilization of the developing phosphonium centre by interaction with the ortho-oxygen atom, previously suggested as being involved in the quaternization of the latter (McEwen et al. 1), is not significant for the quaternization of the phenoxaphosphine (2), and that the predominant role of the ether oxygen is electron-withdrawal from phosphorus. This conclusion is supported by an X-ray structural study of the title compound (3). Crystals of (3) are orthorhombic, a = 18.954(11), b = 25.715(14), c = 9.322(5) a, Z = 8, in space group P b c a (D 15 2h , No. 61). The structure was determined by Patterson and electrondensity methods, and refined by least squares techniques to R = 0.045 for 1505 independent reflections. The fused ring system of the phenoxaphosphonium cation...

Alkali and alkaline-earth metal complexes of 4′-acetobenzo-15-crown-5 and 4′-acetobenzo-18crown-6 have been prepared and characterised by i.r. and n.m.r. spectroscopy. The crystal and molecular structure of 4′-aceto-benzo-18-crown-6·Sr[ClO4]2(the title complex) has been determined. No intermolecular interaction between the metal ion and the aceto-group has been observed. The reaction of several metal salts with 4′-(bromoaceto)benzo-15-crown-5 gives rise to internal nucleophilic displacement of the bromine by the anion to yield novel crown ethers.

Crystals of the title compound are triclinic, a = 8.533(5), b = 11.106(6), c = 8.815(5) Å, a = 107.83(6), β = 104.99(6), γ = 81.30(5)°, Z = 2, space group P1̄. The structure was determined by multisolution direct methods and electron density methods. Refinement by least-squares techniques gave a final R = 0.081 for the 1753 independent reflections. The molecule adopts a butterfly-type conformation such that the fused phenyl rings are inclined to each other at an angle of 56.8°. The P-0 bond distance is 1.506(4) Å; the endocyclic angle at phosphorus is 107.2(3)° and the exocyclic angles vary from 106.5 to 111.9(3)°.

Novel alkaline earth metal thiocyanate complexes are formed by the template condensation of furan-2,5-dicarbaldehyde with 1,11-diamino-3,6,9-trioxaundecane and 1,5-bis(2-aminophenoxy)-3-oxapentane; the X-ray structure of aqua-(3,15-diaza-6,9,12,20-tetraoxabicyclo[15,2,1]eicosa-2,15,17,19-tetraene)-di-isothio-cyanatostrontium(II) has been determined.

Crystals of the title compound are monoclinic, a= 25.685(15), b= 10.444(6), c= 18.818(11), β= 119.18(5)°, Z= 8 in space group C2/c, with the oxygens of water molecules present in the crystals lying along two-fold axes. The structure was determined by Patterson and electron-density methods and refined by least-squares techniques to R= 0.066 for 992 independent reflections. The fused ring system of the dibenzophospholium cation is almost planar and while the exocyclic C–P–C angles lie in the range 110–117°, the endocyclic angle is 93.9°. It is suggested that this low value is consistent with the presence of considerable ring strain, which is relieved either on phosphorane formation following nucleophilic attack at phosphorus, or on dealkylation of dibenzophospholium salts. The implications of ring strain in dibenzophospholium salts are discussed in connection with the possible aromaticity of the dibenzophospholes.

Novel alkaline earth metal thiocyanate complexes are formed by the template condensation of 1,11-diamino-3,6,9-trioxaundecane with pyridine-2,6-dicarbaldehyde; the X-ray structures of (3,15,21-triaza-6,9,12-trioxabicyclo [15.3.1]heneicosa-1(21), 2, 15, 17, 19-pentaene)di-isothiocyanatocalcium(II) and aqua-(3,15,21-triaza-6,9,12-trioxabicyclo[15.3.1]heneicosa-1(21),2,15,17,19-pentaene)di-isothiocyanatostrontium(II) have been determined and the ready exchange of alkaline earth cations for lead(II) in these complexes is reported.