M. Mathew

The preparation and crystal structure of µ-oxido-bis[triphenylphosphinenitrosyliridium(I)]: a novel iridium nitrosyl compound containing a bridging oxygen and a bent metal–metal bond

µ-Oxido-bis[triphenylphosphinenitrosyliridium(I)]–C6H6 has been prepared by the reaction of trans-Ir(CO)Cl(PPh3)2 and nitrite ion in benzene–aqueous alcohol: its structure contains the first example of a bent iridium–iridium bond and a nitrosyl group π-bonded to an iridium atom.

Unusual phosphinoacetylene–iron carbonyl complex: synthesis and X-ray structure of [Fe3(CO)7{Ph2PC(CO2Me)C(CF3)C2(CF3)}(PPh2)]2C6H6

Dodecacarbonyltri-iron reacts with 3,3,3-trifluoropropynyldiphenylphosphine to give a trinuclear iron(O) complex having the Fe3(CO)12skeleton, a new type of delocalized 4-carbon chain, a bridging dipheylphosphido-ligand, and a methoxycarbonyl group derived from both the methanol used as a stabilizer for [Fe3(CO)12] and a CO molecule.

Cycloaddition to a nitrogen-bridged iron complex. Preparation and crystal structure of the maleic anhydride adduct of µ-(3,6-diphenylpyridazine)–hexacarbonyldi-iron

Novel cycloadducts of µ-(3,6-diphenylpyridazine)–hexacarbonyldi-iron with maleic anhydride and acetylenes have been prepared; the molecular structure of the maleic anhydride cycloaddition product has been determined by X-ray structure analysis.

Crystal and molecular structure of acetazolamide (5-acetamido-1,3,4-thiadiazole-2-sulphonamide), a potent inhibitor of carbonic anhydrase

Crystals of the title compound, a potent inhibitor of carbonic anhydrase, are colourless, triclinic, with unit-cell dimensions, a= 5·318(4), b= 9·065(4), c= 9·430(7)A, α= 105·44(2), β= 98·59(2), γ= 100·42(2)°, Z= 2. The structures was solved by the heavy-atom method and refined by least-squares techniques to a final R of 0·028 for 1054 observed reflections. The distances and angles are compared with those in other sulphonamides of varying biological activity. The mechanism of inhibition of carbonic anhydrase is discussed.

Synthesis and crystal structure of an unusal trinuclear ferracyclobutene complex, Fe3(CO)8[Ph2PC4(CF3)2](PPh2)

The molecular structure of a ferracyclobutene complex Fe3(CO)8(Ph2PC4(CF3)2)(PPh2), obtained from the room-temperture reaction of Fe3(CO)12 with Ph2PCCCF3, has been dtermined by X-ray crystallographic techniques.

Novel cleavage of phosphinoacetylene by palladium(II) and platinum(II): preparation and structure of complexes of 1,3-bis(diphenylphosphino)-2-tri-fluoromethylpropene derived from 3,3,3-trifluoropropynyldiphenylphosphine

Unsymmetrical ditertiary phosphine complexes [Ph2PCH2C(CF3)CHPPh2]–MX2(M = Pd or Pt and X = Cl or SCN) have been prepared by reaction of Ph2PCCCF3 with MX42– salts and characterized by an X-ray study of the Pd(SCN)2 derivatives.

Crystal and molecular structure of the 1 : 1 complex of urea and syn-5-nitro-2-furaldehyde oxime

The crystal structure of the title adduct has been determined by X-ray diffraction techniques. The crystals are monoclinic, space group P21/c, Z= 4, with unit-cell dimensions a= 6·571 (2), b= 17·575(7), c= 8·472(3)A, and β= 104·47(3)°. The structure was determined by using a combination of symbolic addition and Patterson methods and was refined by full-matrix least-squares methods to R 0·053 for 1215 observed reflections. The structure consists of hydrogen-bonded layers of nearly planar syn-5-nitro-2-furaldehyde oxime molecules and urea molecules. The distances in the furan ring together with the short C–N (nitro) distance suggest an interaction between the nitro-group and the ring. The absence of a urea adduct of the anti-isomer is discussed.

Reaction of 3,5,7-triphenyl-4H-1,2-diazepine with di-iron nonacarbonyl; the X-ray crystal and molecular structure of a novel iron-containing bicyclo[5,1,1]-system

Reaction of Fe2(CO)9 with 3,5,7-triphenyl-4H-1,2-diazepine leads to cleavage of the N–N bond and formation of a nitrogen bridged complex which has been shown by X-ray crystallography to be a bicyclo[5,1,1]derivative.

The preferred conformation in bronchodilatory agents. The crystal structure of isoproterenol sulfate dihydrate

Abstract The crystal and molecular structure of isoproterenol sulfate dihydrate has been determined by single crystal X-ray diffraction methods. A comparison of the conformations in ephedrine, noradrenalin and isoproterenol suggests a preferred conformation for bronchodilatory drugs.

Resonance interaction in thiophen derivatives. The crystal structure of 2-formylthiophen thiosemicarbazone

The crystal structure determination of 2-formylthiophen thiosemicarbazone has revealed the first example of an interaction between a thiophen ring and a group substituted on the ring.