Tetradentate bis-phosphine ligands (P2N2 and P2S2) and their Rh(III), Ni(II) and 105Rh Complexes: X-ray crystal structures of trans-[RhCl2(L2)]PF6, [Ni(L2)](PF6)2 and μ-O2SO2-[Ni(L5)]2(PF6)2

Cagnolini, Aldo; Ballard, Beau; Engelbrecht, Hendrick P.; Rold, Tammy L.; Barnes, Charles; Cutler, Cathy; Hoffman, Timothy J.; Kannan, Raghuraman; Katti, Kattesh; Jurisson, Silvia S.

doi:10.1016/j.nucmedbio.2010.06.013

« Previous Next »Nuclear Medicine and Biology
Volume 38, Issue 1 , Pages 63-76, January 2011

Tetradentate bis-phosphine ligands (P₂N₂ and P₂S₂) and their Rh(III), Ni(II) and ¹⁰⁵Rh Complexes: X-ray crystal structures of trans-[RhCl₂(L2)]PF₆, [Ni(L2)](PF₆)₂ and μ-O₂SO₂-[Ni(L5)]₂(PF₆)₂

Aldo Cagnolini
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
- Aldo Cagnolini and Beau Ballard contributed equally in this work.
Beau Ballard
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
- Aldo Cagnolini and Beau Ballard contributed equally in this work.
Hendrick P. Engelbrecht
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
- University of Missouri Research Reactor (MURR), Columbia, MO 65211, USA
Tammy L. Rold
- Department of Internal Medicine, University of Missouri, Columbia, MO 65211, USA
- Harry S Truman Memorial VA Hospital, Columbia, MO 65201, USA
Charles Barnes
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
Cathy Cutler
- University of Missouri Research Reactor (MURR), Columbia, MO 65211, USA
Timothy J. Hoffman
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
- Department of Internal Medicine, University of Missouri, Columbia, MO 65211, USA
- Harry S Truman Memorial VA Hospital, Columbia, MO 65201, USA
Raghuraman Kannan
- Department of Radiology, University of Missouri, Columbia, MO 65211, USA
Kattesh Katti
- University of Missouri Research Reactor (MURR), Columbia, MO 65211, USA
- Department of Radiology, University of Missouri, Columbia, MO 65211, USA
- Department of Physics, University of Missouri, Columbia, MO 65211, USA
Silvia S. Jurisson
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
- University of Missouri Research Reactor (MURR), Columbia, MO 65211, USA
- Department of Radiology, University of Missouri, Columbia, MO 65211, USA
- Corresponding author. Department of Chemistry, University of Missouri, Columbia, MO 65211, USA. Tel.: +1 573 882 2107; fax: +1 573 882 2754.

Received 12 May 2010; received in revised form 17 June 2010; accepted 23 June 2010. published online 02 September 2010.

Abstract

Introduction

Tetradentate acyclic and macrocyclic diphosphine ligands (P₂N₂ and P₂S₂) have been synthesized and characterized as potential chelates for Rh(III).

Methods

The coordination complexes [RhCl₂(L1)]Cl, trans-[RhCl₂(L2)]PF₆, [Ni(L2)](PF₆)₂, [Ni(L3)](PF₆)₂, [RhCl₂(L4)]PF₆ and [RhCl₂(L5)]PF₆ have been synthesized and characterized. In addition, radiochemistry studies of the ¹⁰⁵Rh complexes with the ligands N,N′-bis[2-(diphenylphosphino)phenyl]-1,3-diaminopropane (L1), 4,8-diphenyl-1,11-diaza-4,8-diphosphaundecane (L2), 5,9-diphenyl-5,9-diphospha-2,12-dithiatridecane (L3) and 1,4,8,11-tetraphenyl-4,8-diphospha-1,11-dithiaundecane (L4) are reported, including normal mouse biodistributions of ¹⁰⁵Rh–L2.

Results

trans-[RhCl₂(L2)]PF₆ crystallized in the monoclinic space group P2₁/c with a=9.9353(5) Å, b=9.0929(5) Å, c=28.689(1) Å, β=93.1400(10) deg, Z=4, R=0.037 and R_w=0.053. [Ni(L2)](PF₆)₂ crystallized in the monoclinic space group P2₁/c with a=11.9665(6) Å, b=14.8903(7) Å, c=31.148(1) Å, β=91.587(1) deg, Z=8, R=0.056 and R_w=0.083. μ-O₂SO₂-[Ni(L5)]₂(PF₆)₂, an unusual sulfate-bridged Ni(II) dimer, crystallized in the triclinic space group P1 bar with a=15.179(2) Å, b=15.514(2) Å, c=16.128(2) Å, α=105.280(7) deg, β=113.074(6) deg, γ=101.657(8) deg, Z=2, R=0.050 and R_w=0.072.

Conclusions

Phosphine-containing ligands allowed for lower temperatures and lower ethanol concentrations in the formulations for ¹⁰⁵Rh(L) complexation, but at the expense of higher ligand concentrations.

Keywords: Rhodium(III), Rhodium-105, P₂N₂, P₂S₂, Radiotherapy