Structures of trans-[TcCl4{P(CH3)3}2] and [P(C7H7)3{C(CH3)2CH2COCH3}]2[TcCl6

Abstract

Tetrachlorobis(trimethylphosphine)techne- tium, trans-(TcC14(C3H9P)2) (I), Mr = 392.88, mono- clinic, P21/c, a= 6.639 (2), b = 8.443 (3), c= 13.559 (4) A, /3 = 100.73 (2) °, V= 746.7 (4) A 3, Z 2, Dx = 1.738 Mg m -3, ,~(Mo Ka)= 0.71069 )k, # = 1.82 mm-~, F(000) = 390, T = 295 and R = 0.036 for 932 observed reflections. The Tc atom is located on an inversion centre. The Tc--P distances are 2.524(2)A while the Tc--C1 bonds are 2.320 (1) and 2.330 (2) A. Bis((1,1-dimethyl-3-oxobutyl)tris(4- methylphenyl)phosphonium) hexachlorotechnetate, (P(C7HT)3(C6H~IO))(TcC16) (II), Mr = 1118.68, mono- clinic, P2~/c, a=15.120(4), b=11.038(3), c = 21.146 (6) A, /3 = 128.59 (2) °, V= 2759 (1) A 3, Z = 2, Dx = 1.344 Mg m -3, ,~(Mo Ka) = 0.71069/~,,/x = 0.64 mm-~, F(000) = 1158, T = 295 K and R = 0.041 for 3019 observed reflections. The Tc atom of the (TcCI6) 2- anion is located on an inversion center. The Tc--C1 bonds vary from 2.352 (2) to 2.359 (1)/~. The ((CTH7)3PC(CH3)2CH2COCH3) ÷ cation was formed from the reaction of P(p-tolyl)3 with acetone as solvent. Introduction. The chemistry of technetium has recently become very important especially in relation to the use of the isotope 99m in radiopharmacy. 99mTC is an ideal nucleus for diagnostic studies in nuclear medicine. It has been used for several years for bone scanning and recently it has been used to study the heart, brain, kidneys, liver and other organs, and also tumor tissue. A good review on medical diagnostic imaging with complexes of 99mTc has been published by Clarke & Podbielski (1987). The most recent advances in this area were published in a book edited by Nicolini, Bandoli & Mazzi (1990). We have begun a project on the synthesis of new technetium compounds, especially mixed ligand com- plexes, and have prepared several phosphine com- pounds as starting materials for these syntheses. Since small quantities of reactants are used, X-ray