1
|
Gascón E, Otal I, Maisanaba S, Llana-Ruiz-Cabello M, Valero E, Repetto G, Jones PG, Oriol L, Jiménez J. Gold(I) metallocyclophosphazenes with antibacterial potency and antitumor efficacy. Synergistic antibacterial action of a heterometallic gold and silver-cyclophosphazene. Dalton Trans 2022; 51:13657-13674. [PMID: 36040292 DOI: 10.1039/d2dt01963a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One of the most important uses of phosphazenes today involves its biomedical applications. They can also be employed as scaffolds for the design and construction of a variety of ligands in order to coordinate them to metallic drugs. The coordination chemistry of the (amino)cyclotriphosphazene ligand, [N3P3(NHCy)6], towards gold(I) complexes has been studied. Neutral complexes, [N3P3(NHCy)6{AuX}n] (X = Cl or C6F5; n = 1 or 2) (1-4), cationic complexes, [N3P3(NHCy)6{Au(PR3)}n](NO3)n (PR3 = PPh3, PPh2Me, TPA; n = 1, 2 or 3) (6-12) [TPA = 1,3,5-triaza-7-phosphaadamantane] and a heterometallic compound [N3P3(NHCy)6{Au(PPh3)}2{Ag(PPh3)}](NO3)3 (13) have been obtained and characterized by various methods including single-crystal X-ray diffraction for 7, which confirms the coordination of gold atoms to the nitrogens of the phosphazene ring. Compounds 1, 4, 6-13 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria. Both the median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) values are among the lowest found for any gold or silver derivatives against the cell lines and particularly against the Gram-positive (S. aureus) strain and the mycobacteria used in this work. Structure-activity relationships are discussed in order to determine the influence of ancillary ligands and the number and type of metal atoms (silver or gold). Compounds 4 and 8 showed not only maximal potency on human cells but also some tumour selectivity. Remarkably, compound 13, with both gold and silver atoms, showed outstanding activity against both Gram-positive and Gram-negative strains (nanomolar range), thus having a cooperative effect between gold and silver, with MIC values which are similar or lower than those of gentamicine, ciprofloxacin and rifampicine. The broad spectrum antimicrobial efficacy of all these metallophosphazenes and particularly of heterometallic compound 13 could be very useful to obtain materials for surfaces with antimicrobial properties that are increasingly in demand.
Collapse
Affiliation(s)
- Elena Gascón
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-C.S.I.C., Pedro Cerbuna 12, 50009 Zaragoza, Spain.
| | - Isabel Otal
- Grupo de Genética de Micobacterias, Departamento de Microbiología, Pediatría, Radiología y Salud Pública, Universidad de Zaragoza, Zaragoza, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, E-28029 Madrid, Spain
| | - Sara Maisanaba
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - María Llana-Ruiz-Cabello
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - Eva Valero
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área Nutrición y Bromatología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - Guillermo Repetto
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - Peter G Jones
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106, Braunschweig, Germany
| | - Luis Oriol
- Departamento de Química Orgánica, Instituto de Nanociencia y Materiales de Aragón-Facultad de Ciencias, Universidad de Zaragoza-C.S.I.C., Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Josefina Jiménez
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-C.S.I.C., Pedro Cerbuna 12, 50009 Zaragoza, Spain.
| |
Collapse
|
2
|
Metallocene and other transition metal derivatives of phosphazene oligomers and polymers: A retrospective summary. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
3
|
Gascón E, Maisanaba S, Otal I, Valero E, Repetto G, Jones PG, Jiménez J. (Amino)cyclophosphazenes as Multisite Ligands for the Synthesis of Antitumoral and Antibacterial Silver(I) Complexes. Inorg Chem 2020; 59:2464-2483. [PMID: 31984738 DOI: 10.1021/acs.inorgchem.9b03334] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The reactivity of the multisite (amino)cyclotriphosphazene ligands, [N3P3(NHCy)6] and [N3P3(NHCy)3(NMe2)3], has been explored in order to obtain silver(I) metallophosphazene complexes. Two series of cationic silver(I) metallophosphazenes were obtained and characterized: [N3P3(NHCy)6{AgL}n](TfO)n [n = 2, L = PPh3 (2), PPh2Me (4); n = 3, L = PPh3 (3), PPh2Me (5), TPA (TPA = 1,3,5-triaza-7-phosphaadamantane, 6)] and nongem-trans-[N3P3(NHCy)3(NMe2)3{AgL}n](TfO)n [n = 2, L = PPh3 (7), PPh2Me (9); n = 3, L = PPh3 (8), PPh2Me (10)]. 5, 7, and 9 have also been characterized by single-crystal X-ray diffraction, thereby allowing key bonding information to be obtained. Compounds 2-6, 9, and 10 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria strains. Both the IC50 and MIC values revealed excellent biological activity for these metal complexes, compared with their precursors and cisplatin and also AgNO3 and silver sulfadiazine, respectively. Both IC50 and MIC values are among the lowest values found for any silver derivatives against the cell lines and bacterial strains used in this work. The structure-activity relationships were clear. The most cytotoxic and antimicrobial derivatives were those with the triphenylphosphane and [N3P3(NHCy)6] ligands. A significant improvement in the activity was also observed upon a rise in the number of silver atoms linked to the phosphazene ring.
Collapse
Affiliation(s)
- Elena Gascón
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea , Universidad de Zaragoza-CSIC , Pedro Cerbuna 12 , 50009 Zaragoza , Spain
| | - Sara Maisanaba
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología , Universidad Pablo de Olavide , Ctra. Utrera, Km 1 , 41013 Sevilla , Spain
| | - Isabel Otal
- Grupo de Genética de Micobacterias, Departamento de Microbiología, Medicina Preventiva y Salud Pública , Universidad de Zaragoza , Zaragoza 50009 , Spain.,Instituto de Salud Carlos III , CIBER de Enfermedades Respiratorias , E-28029 Madrid , Spain
| | - Eva Valero
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área Nutrición y Bromatología , Universidad Pablo de Olavide , Ctra. Utrera, Km 1 , 41013 Sevilla , Spain
| | - Guillermo Repetto
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología , Universidad Pablo de Olavide , Ctra. Utrera, Km 1 , 41013 Sevilla , Spain
| | - Peter G Jones
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , D-38106 Braunschweig , Germany
| | - Josefina Jiménez
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea , Universidad de Zaragoza-CSIC , Pedro Cerbuna 12 , 50009 Zaragoza , Spain
| |
Collapse
|
4
|
Teasdale I, Brüggemann O. Polyphosphazenes: Multifunctional, Biodegradable Vehicles for Drug and Gene Delivery. Polymers (Basel) 2013; 5:161-187. [PMID: 24729871 PMCID: PMC3982046 DOI: 10.3390/polym5010161] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Poly[(organo)phosphazenes] are a unique class of extremely versatile polymers with a range of applications including tissue engineering and drug delivery, as hydrogels, shape memory polymers and as stimuli responsive materials. This review aims to divulge the basic principles of designing polyphosphazenes for drug and gene delivery and portray the huge potential of these extremely versatile materials for such applications. Polyphosphazenes offer a number of distinct advantages as carriers for bioconjugates; alongside their completely degradable backbone, to non-toxic degradation products, they possess an inherently and uniquely high functionality and, thanks to recent advances in their polymer chemistry, can be prepared with controlled molecular weights and narrow polydispersities, as well as self-assembled supra-molecular structures. Importantly, the rate of degradation/hydrolysis of the polymers can be carefully tuned to suit the desired application. In this review we detail the recent developments in the chemistry of polyphosphazenes, relevant to drug and gene delivery and describe recent investigations into their application in this field.
Collapse
Affiliation(s)
- Ian Teasdale
- Institute of Polymer Chemistry, Johannes Kepler University, 4060, Leonding, Austria;
| | - Oliver Brüggemann
- Institute of Polymer Chemistry, Johannes Kepler University, 4060, Leonding, Austria;
| |
Collapse
|
5
|
Davidson RJ, Ainscough EW, Brodie AM, Harrison JA, Waterland MR. The Nature of the Phosphazene Nitrogen-Metal Bond: DFT Calculations on 2-(Pyridyloxy)cyclophosphazene Complexes. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.200901198] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
6
|
Ainscough EW, Brodie AM, Davidson RJ, Moubaraki B, Murray KS, Otter CA, Waterland MR. Metal−Metal Communication in Copper(II) Complexes of Cyclotetraphosphazene Ligands. Inorg Chem 2008; 47:9182-92. [DOI: 10.1021/ic8008706] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eric W. Ainscough
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| | - Andrew M. Brodie
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| | - Ross J. Davidson
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| | - Boujemaa Moubaraki
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| | - Keith S. Murray
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| | - Carl A. Otter
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| | - Mark R. Waterland
- Chemistry-Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand 4442, and School of Chemistry, Building 23, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
7
|
Simanova SA, Kuznetsova TV, Demidov VN, Aleksandrova EA, Diefenbach U. Synthesis and molecular structure of platinum(II) complexes with cyclotriphosphazenes containing pyridylalkylamino and pyridylmethoxy groups. RUSS J GEN CHEM+ 2007. [DOI: 10.1134/s1070363207110059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
8
|
Chandrasekhar V, Thilagar P, Murugesa Pandian B. Cyclophosphazene-based multi-site coordination ligands. Coord Chem Rev 2007. [DOI: 10.1016/j.ccr.2006.07.005] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
9
|
Jung JH, Pomeroy JC, Zhang H, Wisian-Neilson P. Isolation and Characterization of Nongeminal Cyclic Methylphenylphosphazene Tetramers. J Am Chem Soc 2003; 125:15537-42. [PMID: 14664601 DOI: 10.1021/ja0374168] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heating pure samples of the cyclic phosphazenes, cis- or trans-[Me(Ph)PN](3), yielded mixtures of the cis and trans isomers of the cyclic phosphazene trimers, [Me(Ph)PN](3), and all four geometric isomers of the tetramers, [Me(Ph)PN](4). Varying the temperature and heating times changes the ratio of these components. Following the thermolysis by NMR spectroscopy indicated that only a mixture of the two isomeric trimers occurred initially. Longer heating times produced mixtures of the isomers of the tetramer. Column chromatography and solubility differences were used to separate each of the isomers of the tetramer. Spectroscopic and X-ray crystallographic studies suggest that the four different geometrical isomers of the tetramer can be described as cone, partial cone, 1,2-alternate, and 1,3-alternate by analogy to calix[4]arene.
Collapse
Affiliation(s)
- June-Ho Jung
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275, USA
| | | | | | | |
Collapse
|
10
|
Holloway, CE, Melnik, M. Structural Aspect of Platinum Coordination Compounds: Part II. Monomeric Pt11 Compounds with PtA3B and PtA2B2 Composition. REV INORG CHEM 2003. [DOI: 10.1515/revic.2003.23.2-3.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
11
|
Steiner A, Zacchini S, Richards PI. From neutral iminophosphoranes to multianionic phosphazenates. The coordination chemistry of imino–aza-P(V) ligands. Coord Chem Rev 2002. [DOI: 10.1016/s0010-8545(02)00012-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
12
|
Chandrasekhar V, Krishnan V. Advances in the chemistry of chlorocyclophosphazenes. ADVANCES IN INORGANIC CHEMISTRY 2002. [DOI: 10.1016/s0898-8838(02)53005-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
13
|
Baek H, Cho Y, Lee CO, Sohn YS. Synthesis and antitumor activity of cyclotriphosphazene-(diamine)platinum(II) conjugates. Anticancer Drugs 2000; 11:715-25. [PMID: 11129734 DOI: 10.1097/00001813-200010000-00008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A new class of water-soluble cyclotriphosphazene-(diamine)platinum(II) conjugate drugs [NP(Am-Li2)(Am.PtA2)]3 (Am: dicarboxylic amino acid; A2: diamine) has been synthesized and characterized by means of elemental analysis, multinuclear (1H, 31P, 13C, 195Pt) NMR and IR spectroscopies. All the title compounds were subjected to both in vitro and in vivo assays against the murine leukemia L1210 cell line and selected human tumor cells. Most of the title compounds have shown higher in vivo antitumor activity than cisplatin and carboplatin, and, in particular, [NP(L-Glu-Li2)(L-Glu.Pt(-dach)]3 (Glu=glutamate, dach=trans(+/-)-1,2-diaminocyclohexane) showed extraordinary high activity (ILS>500%) equally against both parent and cisplatin-resistant leukemia L1210 cell lines. Furthermore, this candidate compound (KI 60606) exhibited a wider spectrum of in vitro activity by showing higher cytotoxicity against all the selected human tumor cells than cisplatin and, therefore, was subjected to preclinical studies which are now near completion.
Collapse
Affiliation(s)
- H Baek
- Inorganic Chemistry Laboratory, Korea Institute of Science and Technology, Seoul, South Korea
| | | | | | | |
Collapse
|
14
|
Cho Y, Baek H, Sohn YS. Functionalization of organophosphazene trimers: synthesis and characterization of hexakis(dicarboxylic amino acid ester)cyclotriphosphazenes and their salt derivatives. Polyhedron 1999. [DOI: 10.1016/s0277-5387(99)00042-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
15
|
Chandrasekhar V, Vivekanandan K, Nagendran S, Senthil Andavan GT, N. R.Weathers,, Yarbrough JC, Cordes AW. Cycloalkylaminocyclo- and Polyphosphazenes: X-ray Crystal Structures of gem-Tetrakis(cyclohexylamino)dichlorocyclotriphosphazene and Octakis(cyclopropylamino)cyclotetraphosphazene. Inorg Chem 1998. [DOI: 10.1021/ic980520j] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- V. Chandrasekhar
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - K. Vivekanandan
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - S. Nagendran
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - G. T. Senthil Andavan
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - N. R.Weathers,
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - J. C. Yarbrough
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - A. W. Cordes
- Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India, and Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| |
Collapse
|
16
|
Chen-Yang YW, Hwang JJ, Chang FH. Polyphosphazene Electrolytes. 1. Preparation and Conductivities of New Polymer Electrolytes Based on Poly[bis(amino)phosphazene] and Lithium Perchlorate. Macromolecules 1997. [DOI: 10.1021/ma960289y] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Y. W. Chen-Yang
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taiwan 32023, ROC
| | - J. J. Hwang
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taiwan 32023, ROC
| | - F. H. Chang
- Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taiwan 32023, ROC
| |
Collapse
|
17
|
Diefenbach U, Kretschmann M, Stromburg B. Phosphazenes with (2-Pyridylmethylamino) Groups, I. Syntheses and Crystal Structures of Pentaphenoxy(2-pyridylmethylamino)-cyclotriphosphazene and Its Copper(II) Nitrate, Platinum (II) Chloride, and Cobalt(II) Nitrate Complexes. ACTA ACUST UNITED AC 1996. [DOI: 10.1002/cber.19961291227] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
18
|
Diefenbach U, Kretschmann M, �avdarci �. Synthesis of 3-(aminomethyl)-pyridylpentaphenoxycyclotriphosphazene and its complex formation with copper(II) nitrate. Molecular structure of {Cu[N3P3(OC6H5)5(NHCH2-(3-C5H4N))]2(NO3)2}. MONATSHEFTE FUR CHEMIE 1996. [DOI: 10.1007/bf00807569] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
19
|
|
20
|
Chandrasekhar V, Thomas KRJ. Coordination and organometallic chemistry of cyclophosphazenes and polyphosphazenes. Appl Organomet Chem 1993. [DOI: 10.1002/aoc.590070102] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
21
|
Bertani R, Facchin G, Gleria M. Organometallic and coordination chemistry on phosphazenes Part I. Zn(II), Pd(II) and Pt(II) complexes on Schiff base-containing cyclophosphazenes. Inorganica Chim Acta 1989. [DOI: 10.1016/s0020-1693(00)83403-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
22
|
Schmidpeter A, Steinm�ller F, Sheldrick WS. Ein N/P-Analogon des Cyclotetraphosphazens: Reaktionen und Struktur des Octaphenyl-1,5,2?5,3,4?5,6?5,7,8?5-diazahexaphosphocins und seines PdCl2-Komplexes. Z Anorg Allg Chem 1989. [DOI: 10.1002/zaac.19895790120] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
23
|
|
24
|
Cyclophosphazenes as novel antitumor agents: X-ray crystal structure and donor properties of the hexaziridinocyclotriphosphazene, N3P3(NC2H4)6. J Mol Struct 1980. [DOI: 10.1016/0022-2860(80)85317-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
25
|
Krishnamurthy S, Sau A, Woods M. Cyclophosphazenes. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/s0065-2792(08)60278-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
|