RESUMO
A variable-temperature (VT) crystal structure study of [Fe(TPP)Cl] (TPP(2-) = meso-tetraphenylporphyrinate) and Hirshfeld surface analyses of its structures and previously reported structures of [M(TPP)(NO)] (M = Fe, Co) reveal that intermolecular interactions are a significant factor in structure disorder in the three metalloporphyrins and phase changes in the nitrosyl complexes. These interactions cause, for example, an 8-fold disorder in the crystal structures of [M(TPP)(NO)] at room temperature that obscures the M-NO binding. Hirshfeld analyses of the structure of [Co(TPP)(NO)] indicate that the phase change from I4/m to P1 leads to an increase in void-volume percentage, permitting additional structural compression through tilting of the phenyl rings to offset the close-packing interactions at the interlayer positions in the crystal structures with temperature decrease. X-ray and neutron structure studies of [Fe(TPP)Cl] at 293, 143, and 20 K reveal a tilting of the phenyl groups away from being perpendicular to the porphyrin ring as a result of intermolecular interactions. Structural similarities and differences among the three complexes are identified and described by Hirshfeld surface and void-volume calculations.
Assuntos
Compostos Ferrosos/química , Metaloporfirinas/química , Cristalografia por Raios X , Compostos Ferrosos/síntese química , Metaloporfirinas/síntese química , Modelos Moleculares , Estrutura Molecular , TemperaturaRESUMO
In the United States, employers and employees are increasingly paying a larger portion of the nation's healthcare bill. Preventive measures are being employed by businesses in an effort to contain the escalating costs of employee healthcare. The work site is an ideal setting for health promotion because 130 million Americans are employed and spend one third of their time at work. However, unhealthy workers tend to be the least likely to participate in health promotion activities. Worksite Wellness Programs must be designed to engage segments of the work force with the greatest health needs. Culturally sensitive and appropriate programs must be developed to engage economically challenged minority and other underserved populations.