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The Zn(2+) coordination chemistry and luminescent behavior of two ligands constituted by an open 1,4,7-triazaheptane chain functionalized at both ends with 2-picolyl units and either a methylnaphthyl (L1) or a dansyl (L2) fluorescent unit attached to the central amino nitrogen are reported. The fluorescent properties of the ZnL1(2+) and ZnL2(2+) complexes are then exploited toward detection of anions. L1 in the pH range of study has four protonation constants. The fluorescence emission from the naphthalene fluorophore is quenched either at low or at high pH values leading to an emissive pH window centered around pH = 5. In contrast, in L2 the fluorescence emission from the dansyl unit occurs only at basic pH values. In the case of L1, a red-shifted band appearing in the visible region was assigned to an exciplex emission involving the naphthalene and the tertiary amine of the polyamine chain. L1 forms Zn(2+) mononuclear complexes of ZnH(p)L1((p+2)+) stoichiometry with p = 1, 0, -1. Formation of the ZnL1(2+)species produces a strong enhancement of the L1 luminescence leading to an extended emissive pH window from pH = 5 to pH = 9. Addition of several anions to this last complex leads to a partial quenching effect. On the contrary, the fluorescence emission of L2 is partially quenched upon complexation with Zn(2+) in the same pH window (5 < pH < 9). The lower stability of ZnL2(2+) with respect to ZnL1(2+) suggests a lack of involvement of the sulfonamide group in the first coordination sphere. However, there is spectral evidence for an interesting photoinduced binding of the sulfonamide nitrogen to Zn(2+). While addition of diphosphate, triphosphate, citrate, and D,L-isocitrate to a solution of ZnL2(2+) restores the fluorescence emission of the system (lambda max ca. 600 nm), addition of phosphate, chloride, iodide, and cyanurate do not produce any significant change in fluorescence. Moreover, this system would permit one to differentiate diphosphate and triphosphate over citrate and d, l-isocitrate because the fluorescence enhancement observed upon addition of the first anions is much sharper. The ZnL2(2+) complex and its mixed complexes with diphosphate, triphosphate, citrate, and D,L-isocitrate have been characterized by (1)H, (31)P NMR, and Electrospray Mass Spectrometry.

The antetorsion angle (beta) of the femoral neck and the "retrotorsion" angle (alpha) of the lesser trochanter were measured in 52 female and 34 male femora taken from 46 human cadavers (age at death 80.3 +/- 8.67 years). In addition, the diameter of the femoral head (d) and the length of the femur (l) were measured. As expected, the antetorsion angle varied over a wide range (beta = 10.5 degrees +/- 9.22 degrees). Measurements on right and left demonstrated an asymmetry: beta right = 8.2 degrees +/- 9.14 degrees; beta left = 12.6 degrees +/- 8.99 degrees. The measurements for retrotorsion of the lesser trochanter also varied in a similar way: alpha total = 31.5 degrees +/- 11.8 degrees; alpha right = 35 degrees +/- 10.7 degrees; alpha left = -28 degrees +/- 11.9 degrees. If alpha and beta are combined to couples, a strong regression is visible (r = 0.7657): beta = 29.5 degrees +/- 0.6 . alpha. Thus, the antetorsion angle depends on the retrotorsion angle or vice versa. The measurements of d and l show marked symmetry: d total = 47.4 +/- 3.6 mm; d right = 47.6 +/- 3.6 mm; d left = 47.2 +/- 3.5 mm; l total = 442.7 +/- 24.6 mm; l right = 441.3 +/- 24.4 mm; l left = 444.0 +/- 24.8 mm. Thus, d and l also vary in dependence on each other (r = 0.578). As the length of the femur is determined by body height, there must be a correlation between the diameter of the femoral head and height; that is to say, a short patient will have a small femoral head.