Platinum Metal Complexes of Carbaboranylphophines: Potential Anti Cancer Agents

Ilham Maulana Ilham Maulana, Peter Loennecke Peter Loennecke, Evamarie Hey-Hawkins Evamarie Hawkins


Polyhedral heteroboranes in particular dicarba-closo-dodecaboranes(12) and their organic derivatives have been the subject of intense research for over 40 years due to their unique chemical and physical properties. The initial attraction to dicarba-closo-dodecaboranes(12) In the medicinal chemistry research, was a result of their high boron content and stability to catabolism, which are important criteria for cancer therapy, such as BNCT (boron neutron capture therapy) agents. The coordination compounds of the platinum group metals have also received large interest for their potential application as chemotherapeutic agents, since cis-diamminedichloroplatinum(II), cisplatin, has been reported to have  capability as tumor inhibitor. Hence, applications can be envisioned for related cis platinum complexes. Complex of cis-rac-[PtCl2{1,2-(PRCl)2C2B10H10}] (R=Ph, tBu, NEt2, NPh2) have been synthesized by employing known carbaborane based phosphine ligands of clorophoshino-closo-dodecaborane , with complex of cis-[PtCl2(COD)] (COD = 1,5-cyclooctadiene) in an N2-atmosphere. The obtained complexes possess expected structure configuration, namely cis-rac. The characterization of the complex has been carried out using 1H, 31P, 13C and 11B-NMR (Nuclear Magnetic Resonance), X-ray of single crystals, elemental analysis, IR (infra red) and mass spectroscopy (MS). The 31P{1H} NMR spectra of all the platinum complexes distinctly show the typical platinum satellites which are attributed to 31P-195Pt-coupling, in which the 31P{1H} NMR spectrum exhibits three lines with an intensity ratio of ca.1:4:1. The structure of the platinum complexes consists of a slightly distorted square-planar coordination sphere, in which the platinum atom is bonded to two chlorides and two phosphorus atoms of the chelating carbaboranylphosphine. Thus the platinum atoms exhibit the coordination number four, which is preferred in platinum(II) complexes.

Keywords: Platinum complexes, phosphine ligand, carbaborane

Full Text:



Alexander, R. P., H. J. Schroeder, 1963, Chemistry of Decaborane-Phosphorus Compounds. IV. Monomeric, Oligomeric, and Cyclic phosphino-carboranesl, Inorg. Chem., 2, 1107.

Balema, V. P., S. Blaurock, E. Hey-Hawkins, 1999, The reaction of phenylchloro phosphino substituted dicarba-closo-dodecaboranes(12) with elemental sulfur and molecular structures of rac-bis-phenylchlorophosphino dicarba-closo-dodecaborane and phenylchlorothiophosphino phenyldicarba-closo-dodecaborane, Polyhedron, 18, 545.

Bakun, A. V., Yu. P. Dokuchaev, I. I. Lapidis, Yu. V. Moskovskii, I. M. Skvortsov, B. G. Antokin, USSR Patent, 402241.

Berger, S., S. Braun, H.-O. Kalinowski , 1996, NMR-Spectroscopy of the Non-Metallic Elements, VCH Verlagsgesellschaft mbH, Weinheim

Benn, R., P. W. Jolly, T. Joswig, R. Maynott, K.-P. Schick, 1986, Z. Naturforsch., 41b, 680.

Brauer, G., 1981, Handbuch der Präparativen Anorganischen Chemie, Band III, Ferdinand Enke Verlag, Stuttgart Claver, C., E. Fernandez, A. Gillon, K. Heslop, D. J. Hyett, A. Martorell, A. G. Orpen, P. G. Pringle, 2000, Biarylphosphonites: a class of monodentate phosphorus(III) ligands that outperform their chelating analogues in asymmetric hydrogenation catalysis, Chem. Comm., 961.

Cravotto, G., F. Demartin, G. Palmisano, A. Penoni, T. Radice, S. Tollari, 2005, Novel cyclometallated Pd(II) and Pt(II) complexes with indole derivatives and their use as catalysts in Heck reaction, J. Organomet. Chem., 690, 2017.

Cotton, F. A., 1972, Inorg. Syn., 13, 48.

Dahlenburg, L., S. Mertel, 2001, Chirale Bisphosphane VI. Chelatkomplexe von Platin(II) mit racemischen und optisch reinen trans-Cyclopentan-1,2-diyl-bis(phosphonigsa¨urediester)- und trans-Cyclopentan-1,2-diyl-bis(phosphonigsa¨urediamid)-Liganden: Synthesen, Strukturen und C–H-Aktivierungsreaktionen, J. Organomet. Chem., 630, 221Falius, H., M.

Babin, 1976, Z. Anorg. Allg. Chem., 420, 65.

Gray, G. M., D. C. Smith Jr., C. H. Duffey, 2000, 31P{1H} NMR spectroscopic and X-ray crystallographic studies of conformational dynamics in cis-M{Ph2P(CH2CH2O)5CH2CH2PPh2-P,P} (M_Mo(CO)4, PtCl2) metallacrown ethers, Inorg. Chem., 581, 300-302.

Grim, S. O., R. L. Keiter, W. McFarlane, 1967, A Phosphorus-31 Nuclear Magnetic Resonance Study of Tertiary Phosphine Complexes of Platinum(1I), Inorg. Chem., 6, 1133.

Harada, M., Y. Kai, N. Yasuoka, N. Kasai, 1976, Bull. Chem. Soc. Japan., 49, 3472

Hawthorne, M. F., 1993, Angew. Chem. 105, 997.

Hill, W. E., B. G. Rackley, L. Silva-Trivino, 1983, Inorg. Chem. Acta, 75, 51.

Hush, N. S., J. Schamberger, G. B. Bacskay, 2005, A quantum chemical computational study of the relative stabilities of cis- and trans-platinum dichloride in aqueous solution, Coord. Chem. Rev., 249, 299.

Van Leeuwen, P. W. N. M., P. C. J. Kamer, J. N. H. Reek, P. Dierkes, 2000, Ligand Bite Angle Effects in Metal-catalyzed C-C Bond Formation, Chem. Rev., 100, 2741.

Imori, T., T. Ninomiya, K. Konda, 1992, Jpn. Kokai Tokkyo Koho, 4

Johansson, M. H., T. Malmström, O. F. Wendt, 2001, Chiral platinum(II) complexes. Crystal and molecular structures of cis-[PtPhCl((R,R)-CHIRAPHOS)] and cis-[PtCl2((R,R)-CHIRAPHOS)] Inorg. Chim. Acta, 316, 149.

Kopf-Maier, 1994, Complexes of metals other than platinum as antitumour agents, Eur. J. Clin. Pharmacol, 47, 1.

Larsen, A. S., J. D. Holbrey, F. S. Tham, C. A. Reed, 2000, Designing Ionic Liquids: Imidazolium Melts with Inert Carborane Anions, J. Am. Chem. Soc., 122, 7264.

Leites, L. A., 1992, Vibrational Spectroscopy of Carboranes and Parent Boranes and Its Capabilities in Carborane Chemistry, Chem. Rev., 92, 279

Locher, G. L., 1936, Am. J. Roentgenol. Radium Ther., 36, 1.

Longato, B., S. Bresadola, 1982, Hydridoalkyl- and Hydridoalkenyliridium( 111) Complexes Formed in the Reaction of (Carboranyl)iridium(III) Dihydrides with Alkenes and Alkynes. 1, Inorg. Chem., 21, 168.

Paavola, S., F. Teixidor, C. Viñas, R. Kivekäs, 2002, Pd(II) bromide complexes of 1,2-bis(diphenylphosphino)-1,2-dicarbacloso-dodecaborane. Crystal structures of [PdBr2(1,2-(PPh2)2-1,2-C2B10H10)]CH2Cl2, [PdBr1.133Cl0.867(1,2-(PPh2)2-1,2-C2B10H10)] CH2Cl2 and [PdBrCl0.541Me0.459(1,2-(PPh2)2-1,2-C2B10H10)]/CHCl3, Acta Crystallogr., C58, m237.

Peyrone, M., 1844, Annalen der Chemie und Pharmacie, Band LI, 1 ff.

Perich, J. W., R. B. Johns, 1988, Synthesis, 2, 142.

Rosenberg, B., L. VanCamp, J. E. Trosko, V. H. Mansour, 1969, Nature, 222, 385.

Rozencweig, M., D. D. von Hoff, M. Slovik, 1987, Cis-Diamminochloroplatinum, Ann. Intern. Med., 86, 803.

SHELXTL PLUS, SHELXS, 1990, Program for Crystal Structure Solution, SHELXL, Program for Crystal Structure Determination, XP, Interactive Molecular Graphics, Siemens Analytical X-ray Institute Inc.

Sheldrick, G. M., 1998, SADABS - Program for Empirical Absorption Correction, Göttingen.

Soloway, A. H., W. Tjarks, B. A. Baruum, F. G. Rong, R. F. Barth, I. M. Codogni, J. G. Wilson, 1998, The Chemistry of Neutron Capture Therapy, Chem. Rev., 98, 1515.

Sterzik, A., E. Rys, S. Blaurock, E. Hey-Hawkins, 2001, Synthesis and coordination properties of 1-tert-butylchlorophosphino- and 1,2-bis(tert-butylchlorophosphino)-1,2-dicarba-closo-dodecaborane(12)—molecular structures of rac and meso-1,2-(PtBuCl)2C2B10H10 and (R,R,R,R/S,S,S,S)-[{Cu{1,2-(PtBuCl)2C2B10H10}(Cl)}2], Polyhedron, 20, 3007.

Stadlbauer, S., R. Frank, I. Maulana, P. Loennecke, B. Kirchner, E. Hey-Hawkins, 2009, Synthesis and Reactivity of ortho-Carbaborane-Containing Chiral Aminohalophosphines, Inorg. Chem., 48, 6072-6082.

Sturm, T., W. Weissensteiner, K. Mereiter, T. Kégl, G. Jeges, G. Petölz, L. Kollár, 2000, Platinum complexes of heteroannularly bridged heterobidentate ferrocenyl diphosphine ligands: their molecular structure and their use in catalytic carbonylation reactions, J. Organomet. Chem., 595, 93.

Teixidor, F., C. Viñas, A. Demonceau, R. Nuñez, 2003, Boron clusters: Do they receive the deserved interest?, Pure Appl. Chem., 75, 1305.

Teixidor, F., M. A. Flores, C. Viñas, R. Kivekäs, R. Sillanpää, 1996, Rhodium Complexes with the New Anionic Diphosphine [7,8-(PPh2)2-7,8-C2B9H10]- Ligand, Angew. Chem. Int. Ed. Engl., 35, 2251.

Valliant, J. F., K. J. Guenther, A. S. King, P. Morel, P. Schaffer, O. O. Sogbein, K. A. Stephenson, 2002, The medicinal chemistry of carboranes, Coord. Chem. Rev., 232, 173.

Vasconselos, I. C. F., G. K. Anderson, N. P. Rath, C. D. Spilling, 1998, Preparation and Structure of new homochiral diazaphosphol ligands and their platinum(II) chloride complexes, Tetrahedron: Asymmetry, 9, 927.

Williams, R. E., 1992, The Polyborane, Carborane, Carbocation Continuum: Architectural Patterns, Chem. Rev., 92, 177.

Yinghuai, Z., A. Parthiban, F. B. H. Kooli, 2004, Syntheses and catalytic properties of polystyrene supported nickel(II) carborane complexes, Catalysis Today, 96, 143


Copyright (c) 2017 Indonesian Journal of Cancer Chemoprevention

Indexed by:





Indonesian Society for Cancer Chemoprevention