LABORATORY of X-ray DIFFRACTION

Welcome to the X-ray Diffraction Laboratory in the Central Laboratory of Minearlogy and Crystallography. We are a full service X-ray Diffraction laboratory offering state of the art instrumentation for the analysis of solid materials. Our services include single-crystal and powder diffraction x-ray scattering analysis for Material Sciences, Chemistry, Biochemistry,  and Pharmaceuticals. We are staffed by fully trained Ph.D. scientists who employ the most up to date diffraction and x-ray techniques. Please feel free to contact us about your diffraction needs.

About us

     Laboratory Services 

left to right: Boris Shivachev, Rosica Petrova, Louiza Dimova, Jana Tzvetanova, Ognyan Petrov, Vladislav Kostov

See NEWS for the most recent information on the X-ray Diffraction Laboratory Status

Our Mission The purpose of our laboratory is to provide x-ray diffraction analysis to the Bulgarian Academic and University system. Our main focus is to determine molecular structure from single-crystal samples, to determine shape and size by powder x-ray scattering and to perform high resolution x-ray powder diffraction. We provide services to outside users on a collaborative basis. We are a full service facility, able to determine the three dimensional structure of molecules and solids, from powder and single crystal samples. We can determine various structural types from small inorganic solids to small macromolecules. (see our Brochure)

People  

Head of the Lab

e-mail

Research fields and interests

Associate Professor Rositsa Nikolova, PhD

rosenikolovyahoocom

 

Research and Academic Staff

Professor Ognyan Petrov, PhD

opetrovdirbg

минералогия, кристалография, рентгено-структурен анализ, прахова рентгенография, зеолити, екология и материалознание

Associate Professor Vladislav Kostov, PhD

vkytinhotmailcom

 

Associate Professor Boris Shivachev, PhD

blshivachevgmailcom

biologicaly active compounds, drugs, proteins, peptides, single crystal, macromolecular crystallography, crystal growth, hydrogen bonding and weak interactions, glasses (borate, tellurate), nano-materials characterization (size, size distribution, dispersion, stability in different media)

Assistant Professor Stanislav Ferdov, PhD

stanislav_ferdovhotmailcom

Jana Tzvetanova, MSc, PhD Student

yana_tzmailbg

 

Assistant Professor Louiza Terziyska Dimova, PhD

Louiza.dimovagmailcom

Assistant Professor Milen Kadiysky, PhD

milenchoomailbg

PhD Students
Liliya V. Tzvetanova    
Hristian I. Svirkova
Vencislav Dyulgerov    
Marian Entcheva    

Equipment

Powder X-ray diffractometer D2 Phaser (BrukerAXS), закупен и въведен в експлоатация през м. октомври 2009 г.,  Работи с  набор от специализирани програми за обработка и визуализация на експерименталните данни (Diffrac Studio). Разполага с пълната база данни  (PDF-2, PDF-4) на Международния център за дифракциаонни данни (ICDD) за фазов анализ; Cu лъчение.

Single crystal diffractometer Supernova (Oxford Diffraction -now Agilent), The SuperNova includes:

Single crystal diffractometer CAD4 (Enraf Nonius, Netherlands), закупен през 1985 г., и е въведен в експлоатация през 1986 г., с възможности за прецизни измервания на атомните координати на монокристални проби. Работи със специализиран софтуер за сканиране и обработка на данните до пълна структурна разшифровка. Разполага със структурните бази данни Inorganic Crystal Structure Database (ICSD), Cambridge Structural Database (CSD) и Protein Database (PDB).

Powder X-ray diffractometer ДРОН 3М (Russia), закупен през 1985 г., и е въведен в експлоатация през 1986 г. Работи с локално приспособен компютър и съответни драйвери за стъпков режим на сканиране, както и с набор от специализирани програми за обработка и визуализация на експерименталните данни. Разполага с пълната база данни  (PDF-2, PDF-4) на Международния център за дифракциаонни данни (ICDD) за фазов анализ.
 

Single crystal diffractometer Supernova (Oxford Diffraction)         Powder diffractometer D2 Phaser (BrukerAXS)

Powder diffractometer DRON 3М Single-crystal diffractometer CAD4

In-situ high temperature sample holder for DRON3M powder diffraction

Type of samples:

Oportunities:

Single crystal structural investigation of new phases (mineral, organic, inorganic, biological); 

Powder diffraction analysis:

Research

 

Selected Projects

Education

"Course on X-ray powder diffraction applications" MGU - Sofia,  Associate Professor Ognyan Petrov

Summer School, DAAD, Germany, 2004, 2005, 2006, „X-ray structural analysis and refinement of small molecules” - Associate Professor Rositsa Nikolova

„Physics " Technical University - Sofia and  UCTM Sofia - Associate Prof. Boris Shivachev

X-RAY STRUCTURAL ANALYSES, Associate Prof. Rositsa Nikolova, Associate Prof. Boris Shivachev

 

Short course: Introduction to Crystallography

 

Frequently Asked Questions

X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and scatters into many different directions. From the angles and intensities of these scattered beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their disorder and sundry other information.

  • Single-crystal diffraction is the oldest and most precise method of X-ray crystallography, in which a beam of X-rays strikes a single crystal, producing scattered beams. When they land on a piece of film or other detector, these beams make a diffraction pattern of spots; the strengths and angles of these beams are recorded as the crystal is gradually rotated. Each spot is called a reflection, since it corresponds to the reflection of the X-rays from one set of evenly spaced planes within the crystal. For single crystals of sufficient purity and regularity, X-ray diffraction data can determine the mean chemical bond lengths and angles to within a few thousandths of an Еngstrцm and to within a few tenths of a degree, respectively. The atoms in a crystal are also not static, but oscillate about their mean positions, usually by less than a few tenths of an Еngstrцm. X-ray crystallography allows the size of these oscillations to be measured quantitatively. The main  limitation of the method is the requirement of a pure single crystal of high regularity.
     

  • Powder diffraction is one of the primary techniques used to characterize materials, providing structural information even when the crystallite size is too small for single crystal x-ray diffraction methods.

    There has been a significant increase in the application of powder diffraction in recent years, both in research and manufacturing, fuelled by improved instrumentation, data processing and awareness of the information that can be obtained. Powder diffraction allows for rapid, non-destructive analysis of multi-component mixtures without the need for extensive sample preparation. This gives laboratories the ability to quickly analyze unknown materials and perform materials characterization in such fields as chemistry, materials science, geology, mineralogy, forensics, archaeology, and the biological and pharmaceutical sciences.

Two limiting cases of X-ray crystallography—"small-molecule" and "macromolecular" crystallography—are often discerned. Small-molecule crystallography typically involves crystals with fewer than 100 atoms in their asymmetric unit; such crystal structures are usually so well resolved that the atoms can be discerned as isolated "blobs" of electron density. By contrast, macromolecular crystallography often involves tens of thousands of atoms in the unit cell. Such crystal structures are generally less well-resolved (more "smeared out"); the atoms and chemical bonds appear as tubes of electron density, rather than as isolated atoms. In general, small molecules are also easier to crystallize than macromolecules; however, X-ray crystallography has proven possible even for viruses with hundreds of thousands of atoms.

Gallery

Single crystal structures

  • Minerals

Sr-chabazite

Petrova, R et al. 2005. Single crystal structure analysis of Sr-bearing chabazite from Kayryaka quarry, Bourgas region, Bulgaria, and its Sr-exchanged form. – In: Proc. of the Jubilee Intern. Conf. “80 years BGS”, Sofia, 75–78.

  • New synthetic organic and inorganic phases

With potential non-linear optical activity (NLO SHG)

2-(3-Benzoyl-1-pyridinio)-3,4-dioxocyclobutenolate 2-{3-[(E)-(3,4-Dimethoxyphenyl)ethenyl]-5,5-dimethylcyclohex-2-enylidene}malononitrile
Acta Cryst. C61, 213-215 Acta Cryst., E61, 550-552

Biologicaly active compounds

 

Crystal structure of 6-O-Acetylcodeine Crystal structures and hydrogen bonding sites and direction in (a) 3-amino-cycloheptanespiro-4’-imidazolidine-2’,5’-dione (IA) and (b) cycloheptanespiro-4’-imidazolidine-2’,5’-dione
Acta Cryst., E61, 2582–2584 Cent. Eur. J. Chem. • 7(1) • 2009 • 14-19

 

Powder Diffraction investigations

  • New phases  in ICDD database

PDF# 87-2069 оловно-антимонова хлорсулфосол

PDF# 85-1774 Cs-обменен клиноптилолит
 

  • Rietveld Refinement

Crystal structure of  STS – K2TiSi3O9.H2O with K от Na inclusions(GSAS & FULLPROF).

 Rp=9.96, Rwp=13.31, Chi2=1.35
RB=8.33, RF=6.7

Phosphorites from Gintzi Ore deposit, Bulgaria.

RP – 10.11, RW – 13.17, RB – 3.08
 (wt. %): calcite – 37, fluoroapatite – 37, quartz – 13, шамозит – 9.5, мусковит – 3, санидин – <1.

  • Rietveld Quantitative Phase Analysis of geological samples (FullProf)

(wt. %): anhydrite – 35.9, dolomite – 58.7, and quartz – 5.4

  • Powder diffraction peak profile analysis

Чрез профилен анализ е потвърдено наличие на минерала моганит в ахати от района на гр. Шумен – първи находки за България. В допълнение чрез количествен анализ (модифициран метод на Ритвелд) е установено, че в една от ахатовите проби присъстват 69.0 тегл. % кварц

Links

International Union of Crystallography (IUCr);

European Crystallographic Association (ECA);

Bulgarian Crystallographic Society (BCS)

 

Publications

2010

 

  1.  P. Todorov, E. Naydenova, R. P. Nikolova and B. L. Shivachev, Ammonium hydrogen (RS)-[(5-methyl-2-oxo-1,3-oxazolidin-3-yl)methyl]phosphonate Acta Cryst. (2010). E66, o6 doi:10.1107/S1600536809050338 ]

 2.  Margarita D. Apostolova, Rositsa P. Nikolova and Boris L. Shivachev, 2010. (4-Carbamoylphenyl)boronicacid, ActaCryst. E66, o1273

 

 

2009

 

 1.  R. P. Nikolova, K. Fujiwara, N. Nakayama, V. Kostov-Kytin, 2009. Crystal structure of a new small-pore zirconosilicate Na2ZrSi2O7.H2O and its relation to stoichiometrically and topologically similar compounds. Solid State Sciences 11, 382-388

 2.  P. T. Todorov, R. N. Petrova, E. D. Naydenova, 2009. Structure, conformation and hydrogen bonding of two amino-cycloalkanespiro-5-hydantoins, Cent. Eur. J. Chem 7(1) 14-19.

 3.  T. I. Milenov, P. M. Rafailov , M. V. Abrashev , R. P. Nikolova , R. Titorenkova and M. M. Gospodinov, 2009. Growth and characterization of large La1-xPbxMnO3-δ (x=0.32–0.35) crystals, Cryst. Res. Technol. 44, No. 11, 1192 – 1196.

 4.  Ivayla N. Pancheva, Petar Dorkov, Vasil N. Atanasov, Mariana Miteva, Boris L. shevachev, Rosica P. Nikolova, Heike Mayer-Figge, William S. sheldrick, 2009. Crystal structure and Properties of the copper(II) complex of sodium monensin A, Journal of Inorganic Biochemistry 103, 1419-1424.

 5.  A.V. Egorisheva, T.I. Milenov, P. M. Rafailov, C. Thomsen, R. Petrova, V. M. Skorilov, M. M. Gospodinov, 2009. Lattice distortions in a Bi12SiO20 crystal caused by doping with copper, Solid State Communications, 149, 1616-1618.

 6.  Dobreva, S., Milenov, T., Rafailov, P., Nikolova, R., Comptes Rendus de L'Academie Bulgare des Sciences, 62, 5 (2009), 565-570. Growth, structure and electrical properties of La2CoMnO6 crystals ISSN 1310-1331

 7.  R. Titorenkova, R. Nikolova and B. Mihailova, Effect of doping on the structure of Bi4Ge3O12 ,Acta Cryst A. (2009). A65, s217

 8.  Titorenkova, R., Mihailova, B., Petrova, R., Gospodinov, M., Konstantinov, 2009. L. Effect of doping on the structure and Raman spectra of Bi 4Ge3O12, AIP Conference Proceedings, 1203, 289-293.

 9.  Dobreva, S., Milenov, T., Rafailov, P., Nikolova, R., 2009. Growth, structure and electrical properties of La2CoMnO6 crystals, Comptes Rendus de L'Academie Bulgare des Sciences 62 (5), pp. 565-570

 10.  Shivachev Boris, Nikolova Rositsa, 2009., Hydrogen Bonding in Spirohydantoin Compounds. Acta Cryst. A65, s304

 

 

2008

1.       Ananias, D., Ferdov, S., Paz, F.A. A., Sб Ferreira, R. A., Ferreira, A., Geraldes, C. F. G. C., Carlos, L. D., Lin, Z., Rocha. J. 2008. Multifunctional Layered Lanthanide Silicate Nanoparticles – Chemistry of Materials, (20), 205-212.

2.       Armbruster, T., Kadiyski, M., Reznitsky, L.Z., Sklyarov, E.V., and Galuskin, E.V. 2008. Batisivite, the first silicate related to the derbylite-hemloite group. - European Journal of Mineralogy, 20, 975-981

3.       Atanassova, M., Lachkova, V., Vassilev, N., Shivachev, B., Varbanov, S., & Dukov, I. (2008). Effect of p-tert-butylcalix[4]arene fitted with phosphinoyl pendant arms as synergistic agent in the solvent extraction of trivalent lanthanoids with 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione and structural study of solid complexes by IR, NMR and X-ray. Polyhedron, 27(15), 3306-3312.

4.       Dorkov, P., I.N. Pantcheva, W.S. Sheldrick, H. Mayer-Figge, R. Petrova & M. Mitewa, 2008. Synthesis, structure and antimicrobial activity of manganese(II) and cobalt(II) complexes of thepolyether ionophore antibiotic Sodium Monensin A. J. Inorg.  Biochem. 102 (1),  26-32.

5.       Ferdov, S., Lin, Z., Sб Ferreira R. A., Correia, M. R. 2008, Hydrothermal synthesis, structural, and spectroscopic studies of vanadium substituted ETS-4. Microporous and Mesoporous Materials, 110, (2-3), 1, 436-441.

6.       Ferdov, S., Sб Ferreira, R. A., Lin, Z. 2008. Photoluminescence of Eu3+-doped nanosized microporous titanosilicate – a structural analogue of the mineral pharmacosiderite. - Journal of Alloys and Compounds 451, (1-2), 125-127.

7.       Ferdov, S., R.A. Sб Ferreira, Z. Lin. 2008. Optical properties and local structure of Eu3+–doped synthetic analogue of the microporous titanosilicate mineral sitinakite – Journal of Luminescence, (128), 1108-1112.

8.       Ferdov S, Lin Z, Ferreira R.A.S., 2008, Syntheses of mesoporous and microporous materials via 2-methylpentamethylenediamin. - Chemistry Letters, (37), 100-101.

9.       Ferdov, S.; Reis, M. S.; Lin, Z.; Ferreira, R. A. S.,2008,  Hydrothermal Synthesis, Crystal Structure, and Magnetic Properties of a New Inorganic Vanadium(III) Phosphate with a Chain Structure. - Inorg. Chem., 47, (21), 0062–10066

10.    Galuskin, E.V., Gazeev, V.M., Armbruster, Th., Zadov, A.E., Galuskina, I.O., Pertsev, N.N., Dzierzanowski, P., Kadiyski, M., Gurbanov, A.G., and Wrzalik, R. 2008. Lakargiite CaZrO3 – a new mineral of the perovskite group from the North Caucasus, Kabardino-Balkaria, Russia. - American Mineralogist, 93, 1903-1910.

11.    Galuskina, I.O., Kadiyski, M., Armbruster, T., Galuskin, E.V., Pertsev, N.N., Dzierzanowski, P., Wrzalik, R. 2008. A new natural phase in the system Mg2SiO4 – Mg2BO3F – Mg2BO3(OH): Composition, paragenesis and structure of OH-dominant pertsevite. - European Journal of Mineralogy, 20, 951-964.

12.    Gatta, G.D., Rotiroti, N., Fisch, M., Kadiyski, M., and Armbruster, T. 2008. Stability at high-pressure, elastic behavior and pressure-induced structural evolution of CsAlSi5O12, a potential nuclear waste disposal phase. - Physics and Chemistry of Minerals, 35, 521-533.

13.    Georgieva, G., Gencheva, G., Shivachev, B. L., & Nikolova, R. P. (2008). A new monoclinic polymorph of dichlorido-tetra-kis(dimethyl sulfoxide)-ruthenium(II). Acta Crystallographica Section E: Structure Reports Online, 64(8).

14.    Stoyanova-Ivanova, A. K., Terzieva, S. D., Shivachev, B. L., Mikli, V., & Vladimirova, L. K. (2008). Synthesis and superconducting properties of Nd0.33 Eu0.08Gd0.58Ba2Cu3Оz materials. Central European Journal of Physics, 6(1), 76-79.

15.    Kadiyski, M., Armbruster, T., Galuskin, E.V., Pertsev, N.N., Zadov, A.E., Galuskina, I.O., Wrzalik, R., Dzierzanowski, P., and Kislov, E.V. 2008. The modular structure of dovyrenite, Ca6Zr[Si2O7]2(OH)4: Alternate stacking of tobermorite and rosenbuschite-like units. - American Mineralogist, 93, 456-462.

16.    Kadiyski, M., Armbruster, T., Guenther, D., Reusser, E., Peretti, A. 2008. Johachidolite CaAl[B3O7] a mineralogical and structural peculiarity. - European Journal of Mineralogy, 20, 965-973.

17.    Kolev, T., Koleva, B. B., & Schivachev, B. (2008). Oriented solids as a colloid suspension in nematic liquid crystal - new tool for IR-spectroscopic and structural elucidation of inorganic compounds and glasses. - Inorganica Chimica Acta, 361(7), 2002-2012.

18.    Nikolova, R. P., K. Fujiwara, N. Nakayama & V. Kostov-Kytin. 2008. Structural studies of layered zirconosilicate Na2Zr7Si2.5O20·3H2O and its ion exchanged forms. - Transactions of the materials research society of Japan, (accepted March 25, 2008)

19.    Nikolova, R. P., K. Fujiwara, N. Nakayama, V. Kostov-Kytin. 2008. Crystal structure of a new small-pore zirconosilicate Na2ZrSi2O7.H2O and its relation to stoichiometrically and topologically similar compounds. - Solid State Sciences (in press)

20.    Nikolova, R. P., Kolev, T., Statkova-Abeghe, S. M., & Shivachev, B. L. (2008). (±)-Ethyl 6,7-dimethoxy-1-(1H-pyrrol-2-yl)-1,2,3,4-tetra- hydroisoquinoline-2-carboxylate. Acta Crystallographica Section E: Structure Reports Online, 64(9).

21.    Petrov, P., M. Stoyanova, B. Shivachev. 2008. 4-Methyl-1-phenylquinolin-2(1H)-one. – Acta Cryst., E64, o72.

22.    Petrova, D., V. Marinova, L. Yankova, S. Dobreva, D. Kaisheva, O.Petrov, M. Gospodinov, 2008, Growth and physical properties of Bi-doped Pb2ScNbO6 and Pb2ScTaO6 single crystals. - J. Optoelec. Adv. Mat. (in press)

23.    Shivachev, B., Petrov, P., & Stoyanova, M. (2008). Synthesis and crystal structure of 4-methyl-6H-pyrido[3,2,1-jk]carbazol-6-one. Journal of Chemical Crystallography, 1-4.

24.    Terzieva, S. D., Stoyanova-Ivanova, A. K., Shivachev, B. L., Terzijska, B. M., Zaleski, A. J., Misiorek, H., et al. (2008). Microstructure and thermal properties of quasi-equal rare earth substitution Y0.5Gd0.5Ba2Cu3O6.94 superconductor. Central European Journal of Physics,  1-5.

25.    Todorov, P. T., Petrova, R. N., Naydenova, E. D., & Shivachev, B. L. (2009). Structure, conformation and hydrogen bonding of two amino-cycloalkanespiro-5-hydantoins. Central European Journal of Chemistry, 7(1), 14-19.

2007

1.       Ananias, D., S. Ferdov, F. Almeida Pas, R. Sa Ferreira, A. Ferreira, C. Geraldes, L. Carlos, Z. Lin, J. Rocha. 2007. Photoluminescent layered lanthanide silicate nanoparticles. – Chem. Mater., 20, 205–212.

2.       Bakalova, A., R. Petrova, B. Shivachev, H. Varbanov. 2007. Synthesis and crystal structure of a Pt(II) complex with 3-amino-5-methyl-5-phenylhydantoin. – J. Coord. Chem., 60, 15, 1701–1707.

3.       Dorkov, P., I. N. Pantcheva, W. S. Sheldrick, H. Mayer-Figge, R. Petrova, M. Mitewa. 2007. Synthesis, structure and antimicrobial activity of manganese(II) and cobalt(II) complexes of thepolyether ionophore antibiotic Sodium Monensin A. – J. Inorg. Biochem., 102, 1, 26–32.

4.       Ferdov, S., A. Lopes, Z. Lin, R. Sa Ferreira. 2007. New template-free layered manganese (III) phosphate: hydrothermal synthesis, ab initio structural determination, and magnetic properties. – Chem. Mater., 19, 6025–6029.

5.       Ferdov, S., U. Kolitsch, C. Lengauer, E. Tillmans, Z. Lin, R. Sa Ferreira. 2007. Refinement of the layered titanosilicate AM-1 from single-crystal X-ray diffraction data. – Acta Cryst., E63, i186.

6.       Galuskin, E. V., N. N. Pertsev, T. Armbruster, M. K. Kadiyski, A. E. Zadov, I. O. Galuskina, P. Dzierїanowski, R. Wrzalik, E. V. Kislov. 2007. Dovyrenite, Ca6ZrSi4O14(OH)4 – a new mineral from skarned carbonate xenoliths in basic-ultrabasic rocks of the Dovyren massif, Northern Baikal Region, Russia. – Mineralogica Polonica, 38, 1–21.

7.       Ilieva, A., B. Mihailova, Z. Tsintsov, O. Petrov. 2007. Structural state of microcrystalline opals: A Raman spectroscopic study. – American Mineralogist, 92, 1325–1333.

8.       Kandinska, M. I., I. S. Todorov, B. Shivachev, M. G. Bogdanov. 2007. Trans-rac-2-Hexyl-1-oxo-3-(2-pyridyl)-1,2,3,4-tetrahydroisoquinoline-4-carboxylic acid. - Acta Cryst. E63, o2544–o2546.

9.       Kolev, T., B. Shivachev, R. Petrova. 2007. Phenylpyridinium 3-carboxy-2,3-dihydroxy­propanoate dehydrate. – Acta Cryst., E63, o2511.

10.    Kolev, Т., B. Shivachev, R. Petrova, I. Ivanov, S. Atanasova, S. Statkova. 2007. 1,2,3,4-Tetrahydroisoquinolinium hydrogensquarate. – Acta Cryst., E63, o3353–o3354.

11.    Kolev, Т., D. Yancheva, B. Shivachev, R. Petrova. 2007. The pyridinium-betaine of squaric acid. – Acta Cryst., E63, o3259.

12.    Kostov-Kytin, V., Ferdov, S., Kalvachev, Yu., Mihailova, B., Petrov, O. 2007. Hydrothermal synthesis of microporous titanosilicates. - Microporous and Mesoporous Materials, (105), 232-238.

13.    Milenov, P. M., A. V. Rafailov, V. M. Egorisheva, R. Skorikov, R. Petrova, M. N. Veleva, T. D. Dudkina, C. Thomsen, A. Y. A. Vasilev, M. M. Gospodinov. 2007. XRD and Raman spectroscopic study of Ru and Os doped Bi12SiO20 crystals. – J. Opt. Adv. Mater., 9, 2, February 2007, 293–295.

14.    Milenov, T. I., P. M. Rafailov, R. Petrova, Yu. F. Kargin, M. M. Gospodinov. 2007. X-ray diffraction study of a Bi4Ge3O12 crystal. – Mat. Sci. Eng. B, Solid-State Materials for Advanced Technology, 138, 1, 35–40.

15.    Pekounov, Y., O. E. Petrov. 2007. Bone resembling apatite by amorphous-to-crystalline transition driven self-organization. – J. Mater. Sci: Mater. Med., DOI 10.1007 (electronic version)

16.    Peretti, A., Peretti, F., Tun, N.L., Gunther, D., Hametner K., Bieri, W., Reusser E., Kadiyski, M., and Armbruster, T. .2007. Gem quality johachidolite: occurrence, chemical composition and crystal structure. Contributions to gemology, № 5.

17.    Petrova, R., R. Titorenkova, B. Shivachev. 2007. Isoquinolin-1(2H)-one. – Acta Cryst., E63, o4751.

18.    Stoyanova-Ivanova, A. K., S. D. Terzieva, B. L. Shivachev, V. Mikli, L. K. Vladimirova. 2007. Synthesis and superconducting properties of Nd0:33Eu0:08Gd0:58Ba2Cu3Oz materials. – Centrаl. European Journal of Physics, DOI: 10.2478/s11534-007-0044-3.

19.    Todorova, S., G. Kadinov, K. Tenchev, Yu. Kalvachev, V. Kostov-Kytin. 2007. Particle size and support effects on the complete benzene oxidation by Co and Co-Pt catalysts. – J. of Mat. Sci., 42, 3315–3320.

2006

1.       Bakardjieva, S., V. Stengl, L. Szatmary, J. Lukac, N. Murafa, D. Nizmansky, K. Cizek, J. Jirkovsky, N. Petrova. 2006. Transformation of brookite-type TiO2 nanocrystals to rutile: correlation between microstructure and photoactivity. – J. of Mater. Chem., v. 16, 1709-1716.

2.       Ferdov, S., Z. Lina, R. A. Sб Ferreira. 2006. Incorporation of mixed valence vanadium in the microporous titanosilicate AM-2. – Microporous and mesoporous materials, v. 96, 363-368.

3.       Ferdov S, Ferreira RAS, Lin Z. 2006. Hydrothermal synthesis, structural investigation, photoluminescence features, and emission quantum yield of Eu and Eu-Gd silicates with apatite-type structure. - Chemistry of Materials 18, (25), 5958-5964

4.       Kalvachev, Y., V. Kostov-Kitin, S. Todorova, K. Tenchev, G. Kadinov. 2006. Synthetic kenyaite as catalyst support for hydrocarbon combustion. – Applied catalysis B: Environmental, 66, 192-197.

5.       Karayigit, A., Y. Bulut, G. Karayigit, X. Querol, A. Alastuey, S. Vassilev, C. Vassileva. 2006. Mass balance of major and trace elements in a coal-fired power plant. – Energy Sources, 28, 1311-1320.

6.       Kolev, T., R. Bakalska, B. Shivachev, R. Petrova, 2006. Codeinone. – Acta Cryst., Section E: Structure Reports Online, 62, 1, o255-o257.

7.       Mihaylov, M., E. Ivanova, F. Thibault-Starzyk, M. Daturi, L. Dimitrov, K. Hadjiivanov. 2006. New types of nonclassical iridium carbonyls formed in Ir-ZSM-5: A fourier transform infrared spectroscopy investigation. – J. Phys. Chem. B, 110, 10383-10389.

8.       Petrova, N., B. Shivachev, T. Kolev, R. Petrova. 2006. Sodium hydrogensquarate monohydrate. – Acta Cryst., Section E: Structure Reports Online, 62, 6, m1359-m1361.

9.       Shivachev, B., R. Petrova, E. Naydenova. 2006. 3prime;-aminocyclohexanespiro-52-hydantoin-phenylboronic acid (1/1). – Acta Cryst., Section E: Structure Reports Online, 62, 9, o3887-o3889.

10.    Shivachev, B., R. Petrova, P. Marinova, N. Stoyanov, A. Ahmedova, M. Mitewa. 2006. Four cycloalkanespiro-42 -imidazolidine-22,52 -dithiones. – Acta Cryst., Section C: Crystal Structure Communications, 62, 4, o211-o215.

11.    Todorov, P., E. Naydenova, R. Petrova, B. Shivachev, K. Troev. 2006. [(4,4-dimethyl-2-oxo-1,3-oxazolidin-3-yl)methyl]phosphonic acid. – Acta Cryst., Section C: Crystal Structure Communications, 62, 11, o661-o662.

12.    Videva, V., T. Tosheva, A. Chauvin, S. Shenkov, R. Petrova, R. Scopelliti et al. 2006. Phosphoamide – modified p-tert-butyl calix[4]arene and its sodium complexes: synthesis, coordination ability and structure. – Polyhedron, 25, 11, 2261-2268.