|Title:|| Ligands and cationic complexes thereof with technetium-99m|
|Abstract:||This invention concerns novel bidentate ligands L having two phosphorus or arsenic atoms. Cationic complexes of the ligands with Technetium-99m, e.g. having the formula [TcO.sub.2 L.sub.2 ].sup.+, are useful for body imaging, particularly myocardial imaging. The ligands have the general formula where Q is phosphorus or Z is a --CC-- or --CCC-- or --COC-- groups, the four groups Y are all C1-C8 saturated hydrocarbon or fluorohydrocarbon with 1-3 ether oxygen atoms.|
|Inventor(s):|| Kelly; James D. (Amersham, GB2), Chiu; Kwok W. (Gloucester, GB2), Latham; Ian A. (West Bridgford, GB2) |
|Assignee:|| Amersham International plc (Buckinghamshire, GB2) |
1. A ligand having the formula
where each Q is phosphorus,
Z is a --CC-- or --CCC-- chain or o-phenylene which may be substituted by C1-C3 alkoxy or alkoxyalkyl,
the groups Y may be the same or different and each is a saturated hydrocarbon or saturated fluorohydrocarbon which contains from 2 to 8 carbon atoms and from 1 to 3 ether oxygen atoms, provided that the four groups Y together contain a total of
at least 13 carbon atoms.
2. A ligand as claimed in claim 1, wherein the groups Y may be the same or different and each has the formula
1 is 0 or 1,
m is 1 to 3,
provided that (1+m) is 1 to 3,
n is 1 or 2,
where 1 is 0, R.sup.3 is --C.sub.2 H.sub.5 or i--C.sub.3 H.sub.7 or --CH.sub.2 --CH.sub.x F.sub.3-x
where x is 0 to 2, or
where l is 1, R.sup.1 and/or R.sup.2 is --CH.sub.3 or H and R.sup.3 is --CH.sub.3 or --C.sub.2 H.sub.5
3. A ligand as claimed in claim 2, where m is 1 to 3 and n is 1.
4. A ligand as claimed in claim 2, wherein
Q is phosphorus,
Z is --C.sub.2 H.sub.4 --,
each Y is --C.sub.2 H.sub.4 OC.sub.2 H.sub.5.
5. A ligand as claimed in claim 1, wherein each group Y comprises a 5- or 6- membered alicyclic ring containing 1 or 2 ether oxygen atoms.
6. A ligand as claimed in claim 1, wherein each group Y has the formula:
m is 1 to 3
l is 0 to 1, such that (l+m) is 1 to 3,
R.sup.4 is C1 to C3 alkyl or fluoroalkyl.
7. A ligand as claimed in claim 1, wherein Q is a phosphorus, and the two groups Y attached to each Q are different and are selected from those having the formula
where m is 1 to 3, and R.sup.5 is C1 to C4 alkyl or fluoroalkyl.
8. A cationic complex of technetium-99m with a ligand according to claim 1.
9. A complex as claimed in claim 8 having the formula [TcL.sub.2 X.sub.2 ].sup.+ or [TcL.sub.2 O.sub.2 ].sup.+ where L is the ligand and X is a monodentate ligand for Tc.
10. A complex as claimed in claim 8, having the formula [TcL.sub.2 O.sub.2 ].sup.+ where L is a ligand having the formula (C.sub.2 H.sub.5 OC.sub.2 H.sub.4).sub.2 P--C.sub.2 H.sub.4 --P(C.sub.2 H.sub.4 OC.sub.2 H.sub.5).sub.2.