Abstract: There are described stable fluorescent labels comprising a complex of lanthanide metal and a chelating agent comprising a nucleus which is a triplet sensitizer having a triplet energy greater than that of said lanthanide metal and at least two heteroatom-containing groups which form coordinate complexes with lanthanide metals and a third heteroatom-containing group or heteratom in or appended to the triplet sensitizer. Labeled physiologically active materials useful in specific binding assays such as labeled antigens, heptens, antibodies, hormones and the like comprising the stable fluorescent labels having physiologically active materials adsorbed or bonded thereto are also described.

Abstract: There are described stable fluorescent labels comprising a complex of lanthanide metal and a chelating agent comprising a nucleus which is a triplet sensitizer having a triplet energy greater than that of said lanthanide metal and at least two heteroatom-containing groups which form coordinate complexes with lanthanide metals and a third heteroatom-containing group or heteratom in or appended to the triplet sensitizer. Labeled physiologically active materials useful in specific binding assays such as labeled antigens, heptens, antibodies, hormones and the like comprising the stable fluorescent labels having physiologically active materials adsorbed or bonded thereto are also described.

Abstract: Ion-selective compositions which comprise an ion carrier, a compound capable of solvating the ion carrier, and a supporting matrix are disclosed. The ion carrier useful in this invention is a hemispherand compound represented by the structure: ##STR1## wherein X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are independently alkyl or alkenyl, or any one of X.sub.1, X.sub.2, X.sub.3 and X.sub.4 is taken with one of the others of X.sub.1, X.sub.2, X.sub.3 and X.sub.4 to form an alkylene group or an alkylene group interrupted with hetero atoms; and R represents the atoms necessary to complete a macrocyclic ring structure having from 16 to 19 atoms in the backbone of the ring structure, with the proviso that R contains (a) at least one coordinating site for sodium ions and (b) at least two alkylene groups as part of the ring structure. These compounds and the compositions containing same are particularly useful in ion-selective electrodes.

Abstract: Ion-selective compositions which comprise an ion carrier, a compound capable of solvating the ion carrier, and a supporting matrix are disclosed.The ion carriers of this invention are hemispherand compounds represented by the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently hydrogen, alkyl, alkenyl, cycloalkyl, aryl or a heterocyclic group; and X is benzyl or an electron donating group capable of forming at least one coordinating site for sodium ions. A preferred hemispherand according to this invention is 2'-benzyloxy-3,3"-[2,6-pyridylenebis(methyleneoxymethylene)]-2,2"-tetramet hylenedioxy-5,5',5"-trimethyl-1,1':3',1"-terphenyl. These compounds and the compositions containing same are particularly useful in ion-selective electrodes. Such an electrode is capable of selectively transporting sodium ions in preference to other cations. Dry-operative electrodes using these ion-selective compositions as membranes are also disclosed.