Copper and nickel dihalide complexes, their preparation and the use thereof
AssigneeCiba-Geigy Corporation
InventorBeat Schmidhalter
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Abstract
Compounds of formula I ##STR1## wherein X.sup..crclbar. is Cl.sup..crclbar. or Br.sup..crclbar., M is Cu.sup.2.sbsb..sym. or Ni.sup.2.sbsb..sym., Z is a halogen atom, --NH.sub.2, C.sub.1 -C.sub.4 alkyl or C.sub.2 -C.sub.4 alkoxy, R.sup.1 is H, methyl methoxy, halogen or --NH.sub.2, and A is a group ##STR2## wherein R.sup.2 and R.sup.3 each independently have the same meaning as R.sup.1. The compounds are simultaneously cryochromic or thermochromic and are suitable as warning indicators for cooled or heated structural elements.
Claims8
A compound of formula I ##STR10## wherein X.sup..crclbar. is Cl.sup..crclbar. or br.sup..crclbar.,
- M is Cu.sup.2.sym. or Ni.sup.2.sym.,
- Z is a halogen atom, --NH.sub.2, C.sub.1 -C.sub.4 alkyl or C.sub.2 -C.sub.4 alkyl,
- R.sup.1 is H, methoxy, halogen or --NH.sub.2, and
- a is a group ##STR11## wherein R.sup.2 and R.sup.3 each independently
Dependencies are inferred from the claim text.