Laboratory for Materials in Medicine Pan Research Group at Illinois
Bioengineering at Illinois Engineering for Life University of Illinois at Urbana-Champaign


* Indicates that Dr. Pan is the corresponding author


3D-Printed Multidrug-Eluting Stent from Graphene-Nanoplatelet-Doped Biodegradable Polymer Composite

Santosh K. Misra, Fatemeh Ostadhossein, Ramya Babu, Joseph Kus, Divya Tankasala, Andre Sutrisno, Kathleen A. Walsh, Corinne R. Bromfield, and Pan D*

Advanced Healthcare Materials, Article ASAP

DOI: 10.1002/adhm.201700008

Nanosalina: A Tale of Saline-Loving Algae from the Lake’s Agony to Cancer Therapy

Fatemeh Ostadhossein, Santosh K. Misra, Aaron S. Schwartz-Duval, Brajendra K. Sharma , and Pan D*

ACS Appl. Mater. Interfaces, Article ASAP

DOI: 10.1021/acsami.7b01483

Real-Time Monitoring of Post-Surgical and Post-Traumatic Eye Injuries Using Multilayered Electrical Biosensor Chip

Muhammad S. Khan, Santosh K Misra, Aaron S. Schwartz-Duval, Enrique Daza, Fatemeh Ostadhossein, Matthew Bowman, Akshay Jain, Gina Taylor, Deana McDonagh, Leanne T. Labriola, and Pan D*

ACS Appl. Mater. Interfaces, Article ASAP

DOI: 10.1021/acsami.7b01675

Multi-Shell Nano-CarboScavengers for Petroleum Spill Remediation

Enrique A. Daza, Santosh K. Misra, John Scott, Indu Tripathi, Christine Promisel, Brajendra K. Sharma, Jacek Topczewski, Santanu Chaudhuri, and Pan D*

Sci Rep. 2017

DOI: 10.1038/srep41880

Macromolecularly “Caged” Carbon Nanoparticles for Intracellular Trafficking via Switchable Photoluminescence

Santosh K. Misra, Indrajit Srivastava, Indu Tripathi, Enrique Daza, Fatemeh Ostadhossein, and  Pan D*

J. Am. Chem. Soc., Article ASAP
Paper-Based Analytical Biosensor Chip Designed from Graphene-Nanoplatelet-Amphiphilic-diblock-co-Polymer Composite for Cortisol Detection in Human Saliva

Muhammad Khan, Santosh Misra, Zhen Wang, Enrique Daza, Aaron Schwartz-Duval, Joseph Kus, Debanjan Pan, and Pan D*

Anal. Chem. 2017




Functional carbon nanodots for multiscale imaging and therapy

Fatemeh Ostadhossein and Pan D*

WIREs Nanomed Nanobiotechnol. 2016
Hyperspectral Imaging Offers Visual and Quantitative Evidence of Drug Release from Zwitterionic-Phospholipid-Nanocarbon When Concurrently Tracked in 3D Intracellular Space

Santosh K. Misra, Fatemeh Ostadhossein, Enrique Daza, Elyse V. Johnson, and Pan D*

Adv. Funct. Mater. 2016
Nano-Cesium for Anti-Cancer Properties: An Investigation into Cesium Induced Metabolic Interference

Enrique A. Daza, Santosh K. Misra, Aaron S. Schwartz-Duval, Ayako Ohoka, Callie Miller, and Pan D*

ACS Appl. Mater. Interfaces. 2016, 8 (40), pp 26600–26612
Defined Host–Guest Chemistry on Nanocarbon for Sustained Inhibition of Cancer

Fatemeh Ostadhossein, Santosh K. Misra, Prabuddha Mukherjee, Alireza Ostadhossein, Enrique Daza, Saumya Tiwari, Shachi Mittal, Mark C. Gryka, Rohit Bhargava, Pan D*

Small. 2016;
An anisotropic propagation technique for synthesizing hyperbranched polyvillic gold nanoparticles

Aaron S. Schwartz-Duval, Santosh K. Misra, Prabuddha Mukherjee, Elyse Johnson, Alvin S. Acerbo, and Pan D*

Nano Research. 2016; pp 1-15
Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy

Santosh K. Misra, Prabuddha Mukherjee, Huei-Huei Chang, Saumya Tiwari, Mark Gryka, Rohit Bhargava, and Pan D*

Sci Rep. 2016; 6: 29299.
Pro-haloacetate Nanoparticles for Efficient Cancer Therapy via Pyruvate Dehydrogenase Kinase Modulation

Santosh K. Misra, Mao Ye, Fatemeh Ostadhossein, and Pan D*

Scientific Reports 6, Article number: 28196 (2016)
DOI: 10.1038/srep28196
(−)/(+)-Sparteine induced chirally-active carbon nanoparticles for enantioselective separation of racemic mixtures

Gururaja Vulugundam , Santosh K. Misra , Fatemeh Ostadhossein, Aaron S. Schwartz-Duval, Enrique A. Daza, and Pan D*

Chem Comm,2016, 52, 7513-7516
Carotenoid Nanovector for Efficient Therapeutic Gene Knockdown of Transcription Factor FOXC1 in Liver Cancer

Santosh K. Misra, Tania Ray, Fatemeh Ostadhossein, Bomy Kim, Partha S. Ray, and Pan D*

Bioconjugate Chem,Article ASAP
DOI: 10.1021/acs.bioconjchem.5b00601Biocon Paper
Vibrational Spectroscopy and Imaging for concurrent Cellular Trafficking of Co-localized Doxorubicin and Deuterated Phospholipid Vesicles

S. K. Misra, P. Mukherjee, A. Ohoka, A. S. Schwartz-Duval, S. Tiwari, R. Bhargava, and Pan D*

Nanoscale, 2016
DOI: 10.1039/C5NR079975F


Point-of-service, quantitative analysis of ascorbic acid in aqueous humor for evaluating anterior globe integrity

Manas R. Gartia, Santosh K. Misra, Mao Ye, Aaron Schwartz-Duval, Lisa Plucinski, Xiangfei Zhou, David Kellner, Leanne T. Labriola, Pan D*

Scientific Reports 5, Article number: 16011 (2015)
DOI: 10.1039/srep16011
Regulating Biocompatibility of Carbon Spheres via Defined Nanoscale Chemistry and a Careful Selection of Surface Functionalities

S. K. Misra, H. H. Chang, P. Mukherjee, S. Tiwari, A. Ohoka, and Pan D*

Scientific Reports 5, Article number: 14986 (2015)
DOI: 10.1038/srep14986
Trimodal Therapy: Combining Hyperthermia with Repurposed Bexarotene and Ultrasound for Treating Liver Cancer

S. K. Misra, G. Ghoshal, M. R. Gartia, Z. Wu, A. K. De, M. Ye, C. R. Bromfield, E. M. Williams, K. Singh, K. V. Tangella, L. Rund, K. Schulten, L. B. Schook, P. S. Ray, E. C. Burdette, and Pan D*

ACS Nano, Article ASAP
DOI: 10.1021/acsnano.5b05974
Combinatorial therapy for triple negative breast cancer using hyperstar polymer-based nanoparticles

S. K. Misra, X. Wang, I. Srivastava, M. K. Imgruet, R. W. Graff, A. Ohoka, T. L. Kampert, H. Gao, and Pan D*

Chem. Commun., 2015, Advance Article
DOI: 10.1039/C5CC07709E
Comb Image
Defined Nanoscale Chemistry Influences Delivery of Peptido-Toxins for Cancer Therapy

Misra SK, Mao Y, Kim sPan D*

PLoS ONE 10(6): e0125908.
DOI: 10.1371/journal.pone.0125908
Tunable Luminescent Carbon Nanospheres with Well-Defined Nanoscale Chemistry for Synchronized Imaging and Therapy

Prabuddha MukherjeeSantosh K. MisraMark C. GrykaHuei-Huei ChangSaumya TiwariWilliam L. WilsonJohn W. ScottRohit Bhargava, and Pan D*

Small, 11: 4691–4703
DOI: 10.1002/smll.201500728
Enriched inhibition of cancer and stem-like cancer cells via STAT-3 modulating niclocelles

Santosh K. Misra, Tor W. Jensen, and Pan D*

Nanoscale, 2015, 7, 7127-7132

Graphical abstract: Enriched inhibition of cancer and stem-like cancer cells via STAT-3 modulating niclocelles

A strategy for combating melanoma with oncogenic c-Myc inhibitors and targeted nanotherapy

Pan D*, Kim B, Hu G, Gupta DS, Senpan A, Yang X, Schmieder A, Swain C, Wickline SA, Tomasson MH, Lanza GM.

Nanomedicine (Lond). 2015 Jan;10(2):241-51.
DOI: 10.2217/nnm.14.101
A dual strategy for sensing metals with a nano ‘pincer’ scavenger for in vitro diagnostics and detection of liver diseases from blood samples

Santosh K. MisraBenjamin KimNicholas J. KolmodinPan D*

Colloids and Surfaces B: Biointerfaces 126 (2015) 444–451
DOI: 10.1016/j.colsurfb.2014.12.048


Next Generation Gene Delivery Approaches: Recent Progress and Hurdles

Pan D* – (Guest Editor)

Mol. Pharmaceutics, 2015, 12 (2), pp 299–300
DOI: 10.1021/mp5008635
ανβ3-targeted Copper Nanoparticles Incorporating an Sn 2 Lipase-Labile Fumagillin Prodrug for Photoacoustic Neovascular Imaging and Treatment

Ruiying Zhang, Pan D*, Xin Cai, Xiaoxia Yang, Angana Senpan, John S. Allen, Gregory M. Lanza, and Lihong V. Wang. Theranostics. 2015; 5(2): 124–133.

Theranostics. 2015; 5(2): 124–133.
Next Generation Carbon Nanoparticles for Efficient Gene Therapy

Santosh K. Misra , Ayako Ohoka , Nicholas J. Kolmodin , and Pan D* Mol. Pharmaceutics, 2015, 12 (2), pp 375–385

Mol. Pharmaceutics, 2015, 12 (2), pp 375–385
DOI: 10.1021/mp500742y



Nanoscopic Poly-DNA-Cleaver for Breast Cancer Regression with Induced Oxidative Damage

Misra SK, Kus J, Kim SPan D*Mol. Pharmaceutics, 2014, 11 (11), pp 4218–4227



Defying symmetry: a ‘flowery’ architecture with augmented surface area from gold coated polymeric ‘nanoblooms’

Misra SK, Kim B, Chang HH, Pan D* , RSC Adv., 2014,4, 34303-34306GA


Highly efficient anti-cancer therapy using scorpion ‘NanoVenin’

Misra SK, Mao Y, Kim sPan D*Chem. Commun., 2014,50, 13220-13223

GA (1)


Fumagillin Prodrug Nanotherapy Suppresses Macrophage Inflammatory Response via Endothelial Nitric Oxide

Zhou HF, Yan H, Hu Y, Springer LE, Yang X, Wickline SA, Pan D*, Lanza GM, Pham CTN. . ACS Nano, 2014, 8 (7), pp 7305–7317



Application of a hemolysis assay for analysis of complement activation by perfluorocarbon nanoparticles

Pham CTN, Thomas DG, Beiser J, Mitchell LM, Huang JL, Senpan A, Hu G, Gordon M, Baker NA, Pan D*, Lanza GM, Hourcade DE. . Nanomedicine: NBM 2014;10:651-660



Molecular imaging with computed tomography

Lanza GM, Pan D*: . Contrast Media Mol. Imaging 2014,91–2


Multicolor computed tomographic molecular imaging with noncrystalline high-metal-density nanobeacons

Pan D*, Schirra CO, Wickline SA, Lanza GM. Contrast Media Mol. Imaging 2014, 9 13–25

Nanomedicine: Soft Matter Perspective
Pan D*: . Edited Book, Taylor Francis 2014.


Pan D*, Schirra CO, Wickline SA, Lanza GM. Multicolor Computed Tomographic Molecular Imaging with Non-crystalline High Metal Density Nanobeacons: Contrast Media and Molecular Imaging 2013 (Invited review)

Schirra CO, Roessl E, Koehler T, Brendel B, Thran A, Pan D, Anastasio MA, Proksa R.: IEEE Trans Med Imaging. 2013, 32(7):1249-57.

Wu L, Luderer M, Nelson K, Swain C, Lanza GM, Pan D*: Surface passivation of carbon nanoparticles with branched macromolecules influences near infrared bio-imaging. Theranostics 2013 (In press)

Wu L, Cai X, Zhang R, Nelson K, Shen B, Wang LV, Lanza GM, Pan D*:  A green synthesis of carbon nanoparticles from honey and their use in real-time photoacoustic imaging. Nano Research 2013, 6(5): 312-325 (Front Cover Article, Highlighted)

Pan D*, Kim B, Wang LH, Lanza GM. A Brief Account of Nanoparticle Contrast Agents for Photoacoustic Imaging. 2013 Nanomedicine and Nanobiotechnology (WIRE), (In press)

Pan D* “Theranostic Nanomedicine with Functional Nanoarchitechture” Special thematic issue for Molecular Pharmaceutics 2013; 10(3):781-2. (Invited guest editor)


Pan D*, Schirra CO, Senpan A, Schmieder AH, Roessl E, Stacy JA, Wickline SA, Proska R, Lanza     GM: An Early Investigation of Ytterbium Nanocolloids for Highly Sensitive “Multi-color” Spectral CT Imaging. ACS Nano 2012, 6 (4), 3364-3370.

Schirra CO, Senpan A, Roessl E, Stacy JA, Wickline SA, Proska R, Pan D*: Second Generation Gold Nanobeacons for Robust K-Edge Imaging with Multi-Energy CT. J. Mat. Chem. 201222(43):23071-23077.

Kim B, Schmieder AH, Stacy AJ, Williams TA, Pan D*: Sensitive Biological Detection with a Soluble and Stable Polymeric Paramagnetic Nanocluster.J Am Chem Soc. 2012, 134(25), 10377-80.

Kim B, Yalaz C, Pan D*: Synthesis and characterization of membrane stable bis(arylimino)isoindole dyes and their potential application in nano-biotechnology. Tetrahedron Letters, 2012, 53(32), 4134-4137.

Pan D*, Cai X, Kim B, Senpan A, Wickline SA, Wang LV, Lanza GM: Driving Down the Particle Size of Polymeric Micelles for Extravascular Imaging and Drug Delivery. Advanced Health Materials, 2012, 1(5):582-9.

Pan D*, Cai X, Yalaz C, Senpan A, Wickline SA, Wang LV, Lanza GM: Self-assembled nanostructure from copper neodecanoate for photoacoustic detection of sentinel lymphnodes. ACS Nano 2012, 6 (2), 1260-1267.

Pan D*, Sanyal N, Schmieder AH, Senpan A, Kim B, Yang X, Hu G, Allen JS, Wickline SA, Lanza GM: Synthesis of Lipase-labile and Photo-chemically robust sn-2 fumagillin prodrugs for antiangiogenic therapy. Nanomedicine (UK), 2012,7(10):1507-19.

Zhou HF, Yan H, Senpan A, Wickline SA, Pan D, Lanza GM, Pham CT:Targeted lipase-labile fumagillin prodrug nanoparticles suppress inflammation in a mouse model of rheumatoid arthritis. Biomaterials 2012, 33(33): 8632-40.

Pan D* Nephrogenic Systemic Fibrosis (NSF): What It Really Means for Materials Scientists? J Biotechnol Biomaterial 2012, 2, e109.

Pan D,Lanza GM:  Recent advances in contrast agents for magnetic resonance imaging.  CMR Book Chapter 2012 Textbook of CMR-2nd Edition-Schattauer-Publishers.


Pan D*, Pramanik M, Senpan A, Stacy A, Zhang H, Wickline SA, Wang LV, Lanza GM: Molecular photoacoustic imaging of angiogenesis with integrin targeted gold nanobeacons. Faseb J 2011, 25, 875-882. (Highlighted in many popular science magazines)

Pan D*, Pramanik M, Zhang H, Senpan A, Stacy A, Wickline SA, Wang LV, Lanza GM. Photoacoustic tomography differentiates early vulnerable neoangiogenesis from mature vasculature in vivo. J. Am. Coll. Cardiol, 2011, 57 (14), E1595.

Pan D*, Pramanik M, Wickline SA, Wang LH, Lanza GM: Recent Advances in Colloidal Gold Nanobeacons for Molecular Photoacoustic Imaging. Contrast Media and Molecular Imaging 2011, 6 378-388.

Pan D, Schmieder A, Sanyal N, Yang X, Senpan A, Allen J, Zhang H, Wickline SA, Lanza G. Enhanced antiangiogenic efficacy of prodrug nanoparticles quantified with magnetic resonance imaging. J. Am. Coll. Cardiol, 2011, 57 (14), E1592.

Pan D*, Caruthers SD, Senpan A, Yalaz C, Allen JS, Gaffney PJ, Wickline SA, Lanza, GM: Synthesis of NanoQ, a Copper-Based Contrast Agent, for High-Resolution Magnetic Resonance Imaging Characterization of Human Thrombus. J. Am. Chem. Soc. 2011, 133(24), 9168-9171.

Pan D*, Caruthers SD, Senpan A, Schmieder AH, Wickline SA, Lanza GM: Revisiting an old friend: manganese-based MRI contrast agents. Nanomedicine and Nanobiotechnology, 2011, 3(2), 162-173.

Pan D*, Schmieder A,Wickline SA, Lanza GM: Manganese-based MRI contrast agents: past, present and futures. Tetrahedron 2011, 67(44), 8431-8444.

Pham CTN, Mitchell LM, Huang JL, Lubniewski CM, Schall OF, Kilgore JK, Pan D, Wickline SA, Lanza GM, Hourcade DE. Variable antibody-dependent activation of complement by finctionalized phospholipid nanoparticle surfaces. J Biological Chemistry 2011, 286, 123-130.


Pan D*, Pramanik M, Senpan A, Ghosh S, Wickline SA, Wang LV, Lanza GM:  Near infrared photoacoustic detection of sentinel lymphnodes with gold nanobeacons. Biomaterials 2010, 31, 4088-4093.

Pan D*, Pramanik M, Senpan A, Wickline SA, Wang LV, Lanza GM: A facile synthesis of novel self-assembled gold nanorods designed for near-infrared imaging, J. Nanosci. Nanotech. 2010, 10, 8118-8123.

Pan D, Caruthers SD, Chen J, Winter PM, Senpan A, Schmieder AH, Wickline SA, Lanza GM: Nanomedicine strategies for molecular targets with MR and optical imaging. Future Med. Chem. March 2010, 2(3), 471-490. (Invited review).

Pan D*, Rossel E, Scholmka JP, Caruthers SD, Senpan A, Scott, MJ, Zhang H, Gaffney PJ, Choi ET, Rasche V, Wickline SA, Proksa R, Lanza GM: Computed Tomography in Color:  Molecular Imaging of Ruptured Atherosclerotic Plaque with Fibrin-specific Spectral CT Nanobeacons. Angew Chem Int. Ed., 2010, 49, 9635-9639. (Highlighted in popular science magazines)

Lanza GM, Marsh JN, Hu G, Scott M, Schmieder AH, Caruthers SD, Pan D, Wickline SA: Rationale for a Nanomedicine Approach to Thrombolytic Therapy, Stroke 2010, S42-S44.


Pan D*, Williams T, Senpan A, Allen JS, Scott MJ, Gaffney PJ, Wickline SA, Lanza, GM: Detecting Vascular Biosignatures with a Colloidal, Radio-Opaque Polymeric NanoparticleJ. Am. Chem. Soc. 2009; 131(42):15522-15527.

Pan D*, Pramanik M, Senpan A, Yang X, Scott, MJ, Song KH, Gaffney PJ, Wickline  SA, Wang LV, Lanza GM: Molecular Photo Acoustic Imaging (PAI) with Ligand-Directed Gold Nanobeacons. Angew Chem. Int Ed. 2009, 48, 4170-4173.

Pan D*, Williams T, Senpan A, Allen JS, Scott MJ, Gaffney PJ, Wickline SA, Lanza, GM: Detecting Vascular Biosignatures with a Colloidal, Radio-Opaque Polymeric NanoparticleJ. Am. Chem. Soc. 2009; 131(42):15522-15527.

Pan D*, Senpan A, Caruthers SD, Williams T, Scott MJ, Gaffney PJ, Wickline SA, Lanza, GM: Sensitive and efficient detection of thrombus with fibrin-specific manganese nanocolloids. Chemical Communications. 2009, 22, 3234. (Highlighted as hot article)

Pan D*, Caruthers SD, Wickline SA, Lanza GM: Nanomedicine: Perspective and promises with ligand-directed molecular imaging. European J. Rodiology, 2009, 70, 274-285. (Invited review)

Senpan A, Caruthers SD, Rhee I, Mauro NA, Pan D, Hu G, Scott MJ, Fuhrhop RW, Gaffney PJ, Wickline SA, Lanza GM. Conquering the dark side: colloidal iron oxide nanoparticles. ACS Nano. 2009;3(12), 3917-26.

2008 and before

Pan D*, Caruthers SD, Hu G, Senpan A, Scott, MJ, Gaffney PJ, Wickline  SA, Lanza GM: Ligand-Directed Nanobialys as Theranostic Agent for Drug Delivery and Manganese-Based Magnetic Resonance Imaging of Vascular Targets. J. Am. Chem. Soc. 2008; 130(29):9186-7.

Turner JL, Pan D, Plummer R, Chen Z, Whittaker AK, Wooley KL: Synthesis of Gadolinium Labeled Shell Crosslinked Nanoparticle for Magnetic Resonance Imaging Applications.  Adv. Func. Mat. 2005; 15:1248.

Rossin R, Pan D, Qi K, Turner JL, Welch MJ, Wooley KL: 64Cu-labeled folate-conjugated shell cross-linked nanoparticles for tumor imaging and radiotherapy: synthesis, radio labeling and biological evaluation.  J Nucl. Med. 2005; 46:1210.

Brahma S, Pan D, Ray JK: Molecular recognition: studies on the synthesis of methylene pivotal bis-thio carboxamide derivatives as ditopic receptor for suberic acid. Supramolecular Chemistry 2004; 16:447.

Pan D, Turner JL, Wooley KL: Shell crosslinked nanoparticles designed to target angiogenic blood vessels via avß3 receptor-ligand interactions. Macromolecules 2004; 37:7109.

Becker ML, Remsen EE, Pan D, Wooley KL: Peptide Derivatized Shell Crosslinked (SCK) Nanoparticles. 1) Synthesis and Characterization. Bioconjugate Chemistry 2004; 15:699. (Highlighted As Hot Article) (Cover Article)

Pan D, Turner JL, Wooley KL: Folic acid conjugated nanostructured materials designed for cancer cell targeting. Chemical Communications 2003; 19:2400. (Highlighted; Cover Article)

Pan D, Turner JL, Wooley KL: Folic acid conjugated nanostructured materials designed for cancer cell targeting. Chemical Communications 2003; 19:2400. (Highlighted; Cover Article)

Mahato TK, Pan D, Mal SK, Ray JK: Chlorine directed formylation of chloro indanones under Vilsmier-Haack reaction condition. J. Ind. Chem. Soc. 2003; 80: 969. (special commemorative issue)

Pan D, Kar GK, Ray JK: Indium mediated allylation of beta-chlorovinylaldehydes: a facile one-pot synthesis of 1- chlorohexa-1,5- diene-3-ol derivatives. Synthetic Communications 2003; 3:1- 9.

Pan D, Mal SK, Kar GK, Ray JK: Highly chemoselective method for the synthesis of 4-hydroxy-4-allylcyclohexa-2,5-dienone derivatives by indium-mediated allylation protocol. Tetrahedron 2002; 58:2847-2852.

Ray JK, Gupta S, Pan D, Kar GK: Molecular Recognition: Studies on the synthesis of some bis thiophenecarboxamide derivatives as ditopic receptor to long chain dicarboxylic acids. Tetrahedron 2001; 57:7213-7219.

Pan D, Kar GK, Ray JK, Lin JM, Amin S, Fun HK: Studies on cavity shaped polycyclic fluoro azaarenes: Synthesis of trans-9- fluoro-3,4-dihydroxy 3,4- dihydrobenz

acridine and trans- 11-fluoro-3,4- dihydroxy 3,4 dihydrobenz

acridine as potential proximate carcinogenic metabolite of fluorobenz

acridine. J. Chem. Soc. Perkin Trans 1 2001; 19:2470-2475.

Pan D, Ray JK: Regioselective alkylation of polycyclic thiophene derivatives by butyllithium and alkylhalide. Synthetic Communications 2000; 30:3569-3573.

Pan D, Roy BC, Kar GK, Ray JK: Highly site selective alkylation reaction of bent aza heterocycles by alkyllithium and alkyl halides. J. Chem.Soc. Perkin Trans 1, 2000; 2171-2173.