Prof. Judith A. K. Howard, CBE, FRS
(email at firstname.lastname@example.org)
Single Crystal X-ray Crystallography at Durham
The group is led by Professor Judith A. K. Howard and has a wide range of materials-based research interests. These include experimental charge density analysis, in-situ crystallisation of liquids, ultra-low temperature crystallography, high pressure crystallography, software development, solid-state reactions the study of non-linear optical materials and magnetically interesting materials. In addition,Dr. D.S.Yufit is the contact point for the departmental crystallography service, which is run with the help of all members of the group
Structural Chemistry research spans a wide range of activities, but pivotal is the elucidation of molecular structure by diffraction techniques. In the laboratory this means by X-ray diffraction using single crystal or powder techniques. Neutron diffraction and synchrotron radiation experiments are carried out at Central Facilities and are used in combination with at least some preliminary laboratory studies. Powder diffraction techniques using high intensity neutron or X-ray beams are becoming increasingly powerful, but high resolution molecular structure determinations still rely on single crystal intensity data. Neutron diffraction experiments on single crystals are performed in the special cases where the results cannot be derived by any other technique, for example the location of critical hydrogen atoms. e.g. implicated in important mechanisms; phase changes dependent on hydrogen atom movements, etc.
The ability of neutron diffraction to locate hydrogen atoms precisely arises from the differences in the scattering processes for X-rays and neutrons. In the former, this is by the extra-nuclear electrons and in the latter by the nuclei. The consequences of this are manifold, but for crystallographers this means we can exploit these differences to chemical advantage, e.g. differentiating isotopes of the same elements, e.g. H/D, or differentiating between closely 'adjacent' elements in the periodic table. X-rays are less well adapted to the latter since the difference will be only a matter of 1 or 2 electrons of scattering density, e.g. C, N and O, since the X-ray scattering power of an atom relates directly to its atomic number.
Very high resolution intensity data recorded at low temperatures (2 < T < 100 K) can be used, in conjunction with neutron diffraction data, to determine the distribution of charge density in the molecule as well as the electrostatic potentials at molecular surfaces. These are unique experiments and require long, careful data collections and in Durham we have special cryogenic facilities for such studies.
The majority of our experimental research projects involve recording and analysing variable temperature X-ray data in the laboratory and complementary neutron diffraction data collected on ISIS or at the ILL in Grenoble. We also use the synchrotron sources at diamond, ESRF in Grenoble and PSI in Switzerland, when the problems require very high intensity, finely collimated beams and rapid data collections. In addition, we use the Cambridge Structural Database extensively as a research tool in combination with our own experimental data.
There are also computational projects in molecular modelling and simulations, molecular mechanics and conformational analyses, using existing commercial packages and development software in-house. Statistical studies using the wealth of stored structural information in the various crystallographic databases are routine in the group, from simple searches to sophisticated analyses of reaction pathways and structure/activity correlations. The rapid retrieval and manipulation of large quantities of structural data forms the basis of so-called 'drug design' by the pharmaceutical companies and there is a constant demand for improved parameters for input to 'modelling' software. It is the responsibility (and pleasure) of the crystallographer to furnish accurate data to this community.
The crystallography laboratory is equipped with six CCD and one Image Plate X-ray diffractometers for single crystal analysis. These are manufactured by Bruker, Rigaku and Oxford Diffraction and are used for different types of diffraction experiments. We have, in Durham, unique research facilities for very low temperature X-ray diffraction, the first of these was designed and built in-house a number of years ago, this was the Fddd diffractometer, comprising a high intensity, rotating Mo anode generator and a very substantial Huber 4-circle goniostat, which carries a helium Displex cryorefrigerator and enables us to reach temperatures of 10K controllably. This diffractometer has been upgraded (2009) with modern electronics and a new CCD detector and is used currently for high resolution, high pressure data collections. We have also very recently built and commissioned (2010) a new State-of-the-Art Ultra-low temperature diffractometer that operates from 2K to above RT. The new Huber Eulerian cradle is very robust and carries the 3-stage (2K) cryorefrigerator and the diffractometer is equipped with a high intensity Bruker rotating anode Mo X-ray TXS source and an Apex II detector. The detector and the X-ray source distances to the sample can be varied to suit the experiment. Our other routine low temperature device was designed originally for the SMART diffractometer, but is adaptable to other instruments. This is an Oxford Cryosystems' HELIX, which enables us to reach 30K in open stream mode. These unique capability instruments offer enormous possibilities for new studies in chemical, physical and biochemical crystallography. We have also developed a device for diffraction studies at moderate pressure and low temperature and we use Diamond Anvil Cells for higher pressure studies.
X-ray diffraction zone images showing a solid-state phase transition at 41 K involving a cooperative ordering of a fluxional pseudo-Jahn-Teller Cu(II) system. Note the tripling of one cell axis. (hk0 zone at 42 K and hk0 zone at 40 K) Howard et al (1999), Chem. Commun. , 2245-2246.
"Olex2: A Complete Structure Solution, Refinement and Analysis Program." Dolomanov, O. V., L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann (2009). J. Appl. Cryst. 42: 339-341.
"Structural, Spectroscopic, Electrochemical and Computational Studies of C,C'-diaryl-ortho-carboranes, 1-(4-XC6H4)-2-Ph-1,2-C2B10H10(X = H, F, OMe, NMe2, NH2, OH and O-) . Fox, M. A., C. Nervi, A. Crivello, A. S. Batsanov, J. A. K. Howard, K. Wade and P. J. Low (2009).." J. Solid State Electrochemistry 13: 1483-1495.
"Refractive indices for molecular crystals from the response of X-ray constrained Hartree-Fock wavefunctions." Jayatilaka, D., P. Munshi, M. J. Turner, J. A. K. Howard and M. A. Spackman (2009). Phys. Chem. Chem. Phys. 11: 7209-7218.
"Pressure-induced Cooperative Bond Rearrangement in a Zinc Imidazolate Framework: A High-Pressure Single-Crystal X-Ray Diffraction Study." Spencer, E. C., R. J. Angel, N. R. Ross, B. E. Hanson and J. A. K. Howard (2009) J. Am. Chem. Soc. 131: 4022-4026.
"Molecular van der Waals symmetry affecting bulk properties of condensed phases: melting and boiling points.'' Y. L. Slovokhotov and J. A. K. Howard (2007). Struct.Chem. 18: 477-491.
."New Prototype of Light-Driven Molecular Machine on the Basis of Pseudorotaxane Complex of Dibetaine of Unsaturated Viologen Analogue with Cucurbituril." Vedernikov, A. I., N. A. Lobova, L. G. Kuzmina, Y. A. Stzelenko, J. A. K. Howard, N. M. Alfimov and S. P. Gromov (2007). Russian Nanotechnolgies 2(5-6): 56-60.
"Determination of the hydrogen absorption sites in Zn4O(1,4-benzenedicarboxylate) by single crystal neutron diffraction." Spencer, E. C., J. A. K. Howard, G. J. McIntyre, J. L. C. Rowsell and O. M. Yaghi (2006). Chem.Commun: 278-280.
Simple pressure cell for single-crystal X-ray crystallography, D.S. Yufit and J.A.K. Howard, J. Appl. Cryst. (2005) 38, 583-586.
"Gas Adsorption sites in a Large Pore Metal Organic Framework". J.L.C.Rowsell, E C Spencer, J Eckert, J.A.K.Howard and O.M Yaghi (2005) Science 309, 1350-4
A photomagnetic study of three iron (II) compounds containing ligands from the 2,6-di(pyrazol-l-yl)pyridine series, V.A. Money, J.S. Costa, S. Marcen, G. Chastanet, J. Elhaik, M.A. Halcrow, J.A.K. Howard and J.-F. Letard, Chem. Phys. Lett. (2004) 391, 273-277.
Journal papers: academic
- Mailman, A, Winter, SM, Yu, X, Robertson, CM, Yong, W, Tse, JS, Secco, RA, Liu, Z, Dube, PA, Howard, JAK & Oakley, RT (2012). Crossing the Insulator-to-Metal Barrier with a Thiazyl Radical Conductor. Journal of the American Chemical Society 134(24): 9886-9889.
- K.B. Dillon, N.V. Zorina, D.S. Yufit & J.A.K. Howard (2006). 2,2 ',5,5 '-Tetrakis(trifluoromethyl)biphenyl. Acta Crystallographica Section E 62: O104-O106.
- Batsanov, A.S., Goeta, A.E., Howard, J.A.K., Soto, B. & Au-Alvarez, O. (2006). 2-(4-Chloroanilino)- and 2-(4-methoxyanilino)-1,2-diphenyl-ethanone. Acta crystallographica section C crystal structure communications 62(5): o304-o306.
- S.I. Kozhushkov, T. Preuss, D.S. Yufit, J.A.K. Howard, K. Meindl, S. Ruhl, C. Yamamoto, Y. Okamoto, P.R. Schreiner, B.C. Rinderspacher & A. De Meijere (2006). 4,7,11-triheterotrishomocubanes - Propeller-shaped highly symmetrical chiral molecules derived. Issue European Journal of Organic Chemistry 2006(11): 2590–2600.
- O.V. Chetina, D.S. Yufit & J.A.K. Howard (2006). A 1 1 molecular complex of dicyclohexylamine and cyclohexanone oxime. Acta Crystallographica Section E-Structure Reports Online 62: O2053-O2055.
- Russell, J.M., Parker, A.D.M., Radosavljevic-Evans, I., Howard, J.A.K. & Steed, J.W. (2006). Anion-binding mode in a sulfanylphenyl urea complex solid state symmetry breaking and solution chelation. CrystEngComm 8(2): 119-122.
- Collings, J.C., Batsanov, A.S., Howard, J.A.K. & Marder, T.B. (2006). Arene-perfluoroarene interactions in crystal engineering. Part 14. 1 1 Complexes of octafluoronaphthalene with fluorene and 9,10-dihydrophenanthrene. Canadian journal of chemistry 84(2): 238-242.
- Anderson, C.E., Batsanov, A.S., Dyer, P.W., Fawcett, J. & Howard, J.A.K. (2006). Chelating N-pyrrolylphosphino-N-arylaldimine ligands synthesis, ligand behaviour and applications in catalysis. Dalton Transactions 45: 5362-5378.
- C. E Anderson, D. C. Apperley, A. S. Batsanov, P. W. Dyer & J. A. K. Howard (2006). Concise syntheses of tridentate PNE ligands and their coordination chemistry with palladium(II): a solution- and solid-state study. Dalton Transactions 34: 4134-4145.
- E.N. Ushakov, L.G. Kuz'mina, A.I. Vedernikov, M.S. Kapichnikova, J.A.K. Howard, M. Worner, A.M. Braun, M.V. Alfimov & S.P. Gromov (2006). Crown-containing butadienyl dyes 8. Structures and complexation of chromogenic dithia-15(18)-crown-5(6) ethers. Russian Chemical Bulletin 55(1): 94-100.
- Batsanov, A.S., Collings, J.C., Ward, R.M., Goeta, A.E., Porres, L., Beeby, A., Howard, J.A.K., Steed, J.W. & Marder, T.B. (2006). Crystal engineering with ethynylbenzenes Part 2. Structures of 4-trimethylsilylethynyl-N,N-dimethylaniline, and 4-ethynyl-N,N-dimethylaniline with Z '=12 and a single-crystal to single-crystal phase transition at 122.5 +/- 2 K. CrystEngComm 8: 622-628.
- R. Mondal, J.A.K. Howard, R. Banerjee & G.R. Desiraju (2006). Crystallographic studies of supramolecular synthons in amine solvates of trans-1,5-dichloro-9,10-diethynyl-9,10-dihydroanthracene-9,10-diol. Crystal Growth & Design 6(11): 2507-2516.
- A.V. Churakov, D.P. Krut'ko, M.V. Borzov, R.S. Kirsanov, S.A. Belov & J.A.K. Howard (2006). Di-mu-pyridyl-1 2 kappa N-2 C-2 2 1 kappa(2) N C-2-mu-tetrahydrofuran-kappa O-2 O-bis bromo( tetrahydrofuran)magnesium(II) tetrahydrofuran hemisolvate. Acta Crystallographica Section E-Structure Reports Online 62: M1094-M1096.
- A.V. Churakov, O.V. Chetina & J.A.K. Howard (2006). Dicyclohexylamine hydrogen peroxide hemisolvate. Acta Crystallographica Section E-Structure Reports Online 62: O3503-O3505.
- M.R. Crampton, T.A. Emokpae, C. Isanbor, A.S. Batsanov, J.A.K. Howard & R. Mondal (2006). Effects of ortho- and para-ring activation on the kinetics of SNAr reactions of 1-chloro-2-nitro- and 1-phenoxy-2-nitroberizenes with aliphatic amines in acetonitrile. (5): 1222-1230.
- L.J. Farrugia, C.S. Frampton, J.A.K. Howard, P.R. Mallinson, R.D. Peacock, G.T. Smith & B. Stewart (2006). Experimental charge-density study on the nickel(II) coordination complex Ni(H3L) NO3 PF6 H3L = N,N ',N ''-tris(2-hydroxy-3-methylbutyl)-1,4,7-triaza-cyclononane a reappraisal. Acta Crystallographica Section E-Structure Reports Online 62: 236-244.
- L.F. Lourie, Y.A. Serguchev, G.V. Shevchenko, M.V. Ponomarenko, A.N. Chernega, E.B. Rusanov & J.A.K. Howard (2006). Fluorolactonization of norbornenecarboxylic acids and their methyl esters with F-TEDA-BF4 and XeF2. Journal Of Fluorine Chemistry 127(3): 377-385.
- S.R. Parsons, L.K. Thompson, S.K. Dey, C. Wilson & J.A.K. Howard (2006). High-spin 2x2 (Fe2Ni2II)-Ni-III heterometallic square grid with an S=3 ground state. Inorganic Chemistry 45(22): 8832-8834.
- Fox, M.A., Baines, T.E., Albesa-Jove, D., Howard, J.A.K. & Low, P.J. (2006). Improved syntheses of bis(ethynyl)-para-carboranes, 1,12-(RC C)(2)-1,12-C2B10H10 and 1,10-(RC equivalent to C)(2)-1,10-C2B8H8 (R = H or Me3Si). Journal of organometallic chemisty 691(18): 3889-3894.
- A.I. Ibraheem,, D.N. Mkhalid, , D.A-J. Coventry, , A.S. Batsanov, , J.A.K Howard, , R.N. Perutz, & T.B. Marder (2006). Ir-Catalyzed borylation of C-H bonds in N-containing heterocycles: Regioselectivity in the synthesis of heteroaryl boronate esters. Angewandte Chemie International Edition 45(3): 489-491.
- A.J. Wilkinson, H. Puschmann, J.A.K. Howard, C.E. Foster & J.A.G. Williams (2006). Luminescent complexes of iridium(III) containing N boolean AND C boolean AND N-coordinating terdentate ligands. Inorganic Chemistry 45(21): 8685-8699.
- Khairul, W.M., Porres, L., Albesa-Jove, D., Senn, M.S., Jones, M., Lydon, D.P., Howard, J.A.K., Beeby, A., Marder, T.B. & Low, P.J. (2006). Metal cluster terminated "molecular wires". Journal of cluster science 17(1): 65-85.
- Yufit, D.S., Turner, M.J. & Howard, J.A.K. (2006). N,N-diethyl-5-nitropyridin-2-amine. Acta crystallographica section E structure reports online 62(4): o1237-o1239.
- Blatch, A.J., Howard, J.A.K., Probert, M.R. & Whiting, A. (2006). N-(diphenylphosphinoyl)hydroxylamine. Acta crystallographica section E structure reports online 62(11): o5343-o5345.
- Cowan, J.A., Howard, J.A.K., Mason, S.A., McIntyre, G.J., Lo, S.M.F., Mak, T., Chui, S.S.Y., Cai, J.W., Cha, J.A. & Williams, I.D. (2006). Neutron diffraction studies of the 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid and 4,4 '-bipyridine. Acta crystallographica section C crystal structure communications 62(4): o157-o161.
- A. L. Thompson, D. Parker, D. A. Fulton, J. A. K. Howard, S. U. Pandya, H. Puschmann, K. Senanayake, P. A. Stenson, A. Badari, M. Botta, S. Avedano & S. Aime (2006). On the role of the counter-ion in defining water structure and dynamics: order, structure and dynamics in hydrophilic and hydrophobic gadolinium salt complexes. Dalton Transactions 47: 5605-5616.
- Stromnova, T.A., Shishilov, O.N., Dayneko, M.V., Monakhov, K.Y., Churakov, A.V., Kuz'mina, L.G. & Howard, J.A.K. (2006). Palladium(I) carbonyl carboxylate clusters cyclo- Pd-2(mu-CO)(2)(mu-OCOR)(2) (n) (n=2 or 3) structure and reactivity. Journal of organometallic chemisty 691(18): 3730-3736.
- Kuz'mina, L.G., Vedernikov, A.I., Lobova, N.A., Howard, J.A.K., Strelenko, Y.A., Fedin, V.P., Alfimov, M.V. & Gromov, S.P. (2006). Photoinduced and dark complexation of unsaturated viologen analogues containing two ammonium tails with cucurbituril. New journal of chemistry 30(3): 458-466.
- Carbonera, C., Costa, J.S., Money, V.A., Elhaik, J., Howard, J.A.K., Halcrow, M.A. & Letard, J.F. (2006). Photomagnetic properties of iron(II) spin crossover complexes of 2,6-dipyrazolylpyridine and 2,6-dipyrazolylpyrazine ligands. Dalton transactions (25): 3058-3066.
- Yufit, D.S., Chetina, O.V. & Howard, J.A.K. (2006). Polymorphism of non-linear optical material N-(4-nitrophenyl)-N-methylamino-acetonitrile (NPAN). Journal of molecular structure 784(1-3): 214-221.
- Blatch, A.J., Howard, J.A.K., Probert, M.R., Smethurst, C.A. & Whiting, A. (2006). Potassium 4-nitrophenylsulfonate monohydrate. Acta crystallographica section E structure reports online 62(4): m741-m743.
- Batsanov, A.S., Clegg, W., Copley, R.C.B., Fox, M.A., Gill, W.R., Grimditch, R.S., Hibbert, T.G., Howard, J.A.K., MacBride, J.A.H. & Wade, K. (2006). Preparative and structural studies on sulfur-linked carborane icosahedra: 2-phenyl-ortho-carboranyl-sulfur systems (2-Ph-1,2-C2B10H10)(2)X (X = S, S-2 or SO), and ortho-carboran-di-yl systems (1,2-C2B10H10Y)(2) (Y = S or SO). Polyhedron 25(2): 300-306.
- A.S. Batsanov, R.C.B. Copley, M.G. Davidson, M.A. Fox, T.G. Hibbert, J.A.K. Howard & K. Wade (2006). Reactions of icosahedral carboranes with iminotris(dimethylamino)phosphorane HNP(NMe2)(3): A deboronation intermediate nido-C2B10H12 center dot N(H)P(NMe2)(3), deboronation reactions and hydrogen-bonded closo-carborane systems. 17(1): 119-137.
- J.L. Shaw, J. Wolowska, D. Collison, J.A.K. Howard, E.J.L. McInnes, J. McMaster, A.J. Blake, C. Wilson & M. Schroder (2006). Redox non-innocence of thioether macrocycles: Elucidation of the electronic structures of mononuclear complexes of gold(II) and silver(II). Journal of the American chemical society 128(42): 13827-13839.
- L.N. Dawe, T.S.M. Abedin, T.L. Kelly, L.K. Thompson, D.O. Miller, L. Zhao, C. Wilson, M.A. Leech & J.A.K. Howard (2006). Self-assembled polymetallic square grids ([2 × 2] M4, [3 × 3] M9) and trigonal bipyramidal clusters (M5)—structural and magnetic properties. Journal of materials chemistry 16(26): 2645-2659.
- Russell, J.M., Parker, A.D.M., Radosavljevie-Evans, I., Howard, J.A.K. & Steed, J.W. (2006). Simultaneous anion and cation binding by a simple polymer-bound ureidopyridyl ligand. Chemical communications 2006(3): 269-271.
- de Meijere, A., Khlebnikov, A.F., Kozhushkov, S.I., Yufit, D.S., Chetina, O.V., Howard, J.A.K., Kurahashi, T., Miyazawa. K., Frank, D., Schreiner, P.R., Rinderspacher, B.C., Fujisawa, M., Yamamoto, C. & Okamoto, Y. (2006). Syntheses and Properties of Enantiomerically Pure Higher (n ≥ 7) [n−2]Triangulanedimethanols and σ-[n]Helicenes. Chemistry a European journal 12(22): 5697-5721.
- Senanayake, K., Thompson, A.L., Howard, J.A.K., Botta, M. & Parker, D. (2006). Synthesis and characterisation of dimeric eight-coordinate lanthanide(III) complexes of a macrocyclic tribenzylphosphinate ligand. Dalton transactions (45): 5423-5428.
- Adams, C.J., Baber, R.A., Batsanov, A.S., Bramham, G., Charmant, J.P.H., Haddow, M.F., Howard, J.A.K., Lam, W.H., Lin, Z.Y., Marder, T.B., Norman, N.C. & Orpen, A.G. (2006). Synthesis and reactivity of cobalt boryl complexes. Dalton Transactions 11: 1370-1373.
- Vatsadze, S.Z., Manaenkova, M.A., Sviridenkova, N.V., Zyk, N.V., Krut'ko, D.P., Churakov, A.V., Antipin, M.Y., Howard, J.A.K. & Lang, H. (2006). Synthesis and spectroscopic and structural studies of cross-conjugated dienones derived from cyclic ketones and aromatic aldehydes. Russian chemical bulletin 55(7): 1184-1194.
- Abu-Salah, O.M., Ja'far, M.H., Al-Ohaly, A.R., Al-Farhan, K.A., Al-Enzi, H.S., Dolomanov, O.V. & Howard, J.A.K. (2006). Synthesis and Structural Characterization of a Halide-Free Rhombohedral Silver-Alkynyl Cage Complex [Ag14(C2tBu)12][BF4]2. European journal of inorganic chemistry 2006(12): 2353-2356.
- Ward, R.M., Batsanov, A.S., Howard, J.A.K. & Marder, T.B. (2006). Synthesis and structure of an unusual di-rhodium diarylbutadiyne pi-complex featuring a mu-(1,2-eta(2):(3,4-eta(2)-p-CF3C6H4-C C-C C-C6H4-p-CF3 moiety. Inorganica chimica acta 359(11): 3671-3676.
- A.J. Blatch, O.V. Chetina, J.A.K. Howard, L.G.F. Patrick, C.A. Smethurst & A. Whiting (2006). Synthesis and structure of bifunctional N-alkylbenzimidazole phenylboronate derivatives. Organic & Biomolecular Chemistry 4(17): 3297-3302.
- Zhu, X.J., Ward, R.M., Albesa-Jove, D., Howard, J.A.K., Porres, L., Beeby, A., Low, P.J., Wong, W.K. & Marder, T.B. (2006). Synthesis of new mer,trans-rhodium(III) hydrido-bis(acetylide) complexes: Structure of mer,trans- (PMe3)(3)Rh(C equivalent to C-C6H4-4-NMe2)(2)H. Inorganica chimica acta 359(9): 2859-2863.
- Z. Yuan, C.D. Entwistle, J.C. Collings, D. Albesa-Jove, A.S.Batsanov, J.A.K. Howard, N.J. Taylor, H.M. Kaiser, D.E. Kaufmann, S.Y. Poon, W.Y. Wong, C. Jardin, S. Fathallah, A. Boucekkine, J.F. Halet & T.B. Marder (2006). Synthesis, crystal structures, linear and nonlinear optical properties, and theoretical studies of (p-R-phenyl)-, (p-R-phenylethynyl)-, and (E)-[2-(p-R-phenyl)ethenyl]dimesitylboranes and related compounds. Chemistry. A European Journal 12(10): 2758-2771.
- D. Das, R. Banerjee, R. Mondal, J.A.K. Howard, R. Boese & G.R. Desiraju (2006). Synthon evolution and unit cell evolution during crystallisation. A study of symmetry-independent molecules (Z′ > 1) in crystals of some hydroxy compounds. Chemical communications 2006(5): 555-557.
- Banerjee, R., Mondal, R., Howard, J.A.K. & Desiraju, G.R. (2006). Synthon robustness and solid-state architecture in substituted gem-alkynols. Crystal growth & design 6(4): 999-1009.
- Blatch, A.J., Howard, J.A.K., Probert, M.R., Smethurst, C.A. & Whiting, A. (2006). tert-Butyl N-(phosphinoyloxy)carbamate. Acta crystallographica section E structure reports online 62(11): o5346-o5348.
- Spencer, E.C., Howard, J.A.K., Baruah, P.K. & Sanjayan, G.J. (2006). The solid-state behaviour of 4,6-dioxo-5,5-diethylenepyrimidine-2-isobutylurea. CrystEngComm 8(6): 468-472.
- Smith, M.E., Cordiner, R.L., Albesa-Jove, D., Yufit, D.S., Hartl, F., Howard, J.A.K. & Low, P.J. (2006). The synthesis, structure, and electrochemical properties of Fe(C≡CC≡N)(dppe)Cp and related compounds. Camadian journal of chemistry 84(2): 154-163.
- Cordiner, R.L., Smith, M.E., Batsanov, A.S., Albesa-Jove, D., Hartl, F., Howard, J.A.K. & Low, P.J. (2006). The synthesis, structure, reactivity and electrochemical properties of ruthenium complexes featuring cyanoacetylide ligands. Inorganica chimica acta 359(3): 946-961.
- Lermontova, E.K., Selina, A.A., Karlov, S.S., Churakov, A.V., Howard, J.A.K., Oprunenko, Y.F., Antipin, M.Y., Sundermeyer, J. & Zaitseva, G.S. (2006). The transannular interaction germanium-nitrogen in germocanes the influence of substituents. Journal of organometallic chemisty 691(26): 5710-5724.
- Zaitsev, K.V., Karlov, S.S., Selina, A.A., Oprunenko, Y.F., Churakov, A.V., Neumueller, B., Howard, J.A.K. & Zaitseva, G.S. (2006). Titanium complexes of dialkanolamine ligands: Synthesis and structure. European journal of inorganic chemistry 2006(10): 1987-1999.
- Cordiner, R.L., Feroze, M.P., Lledo-Fernandez, C., Albesa-Jove, D., Howard, J.A.K. & Low, P.J. (2006). Trimetallic complexes featuring Group 10 tetracyanometallate dianions as bridging ligands. Inorganica chimica acta 359(11): 3459-3466.
- Howard, JAK (2008). Olex2. OlexSys.