Low-Melting Manganese (II)-Based Ionic Liquids: Syntheses, Structures, Properties and Influence of Trace Impurities

The synthesis of more than 10 new magnetic ionic liquids with [MnX₄]^2- anions, X = Cl, NCS, NCO, is presented. Detailed structural information through single-crystal X-ray diffraction is given for (DMDIm)[Mn(NCS)₄], (BnEt₃N)₂[Mn(NCS)₄], and {(Ph₃P)₂N}₂[Mn(NCO₄)]·0.6H₂O, respectively. All compounds consist of discrete anions and cations with tetrahedrally coordinated Mn (II) atoms. They show paramagnetic behavior as expected for spin-only systems. Melting points are found for several systems below 100 °C classifying them as ionic liquids. Thermal properties are investigated using differential scanning calorimetry (DSC) measurements. The physicochemical properties of density, dynamic viscosity, electrolytic conductivity, and surface tension were measured temperature-dependent of selected samples. These properties are discussed in comparison to similar Co containing systems. An increasing amount of bromide impurity is found to affect the surface tension only up to 3.3%.

Vapor pressure of ionic liquids at low temperatures from AC-chip-calorimetry

The very low vapor pressure of ionic liquids is challenging to measure. At elevated temperatures the liquids might start to decompose, and at relatively low temperatures the vapor pressure becomes too low to be measured by conventional methods. In this work we developed a highly sensitive method for mass loss determination at temperatures starting from 350 K. This technique is based on an alternating current calorimeter equipped with a chip sensor that consists of a free-standing SiNx-membrane (thickness <1 μm) and a measuring area with lateral dimensions of the order of 1 mm. A small droplet (diameter ca. 600 μm) of an ionic liquid is vaporized isothermally from the chip sensor in a vacuum-chamber. The surface-to-volume-ratio of such a droplet is large and the relative mass loss due to evaporation is therefore easy to monitor by the changing heat capacity (J K(-1)) of the remaining liquid. The vapor pressure is determined from the measured mass loss rates using the Langmuir equation. The method was successfully tested for the determination of the vapor pressure and the vaporization enthalpy of an archetypical ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf2]). The data set created in this way in an extremely broad temperature range from 358 K to 780 K has allowed the estimation of the boiling temperature of [EMIm][NTf2]. The value (1120 ± 50) K should be considered as the first reliable boiling point of the archetypical ionic liquid obtained from experimental vapor pressures measured in the most possible close proximity to the normal boiling temperature.

Stability studies of ionic liquid [EMIm][NTf2] under short-term thermal exposure

Mass spectrometer coupled TG analysis was used to identify decomposition products of thermally highly stressed ionic liquids.

Risk perception and psychological strain in women with a family history of breast cancer

BACKGROUND

The thinking in health psychology is that patients' willingness to adopt preventive health behavior is contingent on their perceiving an increased risk of disease and is influenced by accompanying psychological stress. In counseling women with a family history of breast cancer, physicians focus on encouraging the patient to undergo early detection examinations as recommended. Therefore, it is essential to examine how women in this risk group perceive their own chances of developing breast cancer and to assess the psychological effects of their situation.

MATERIAL AND METHODS

129 women with at least one first or second degree relative who had developed breast cancer were enrolled in a questionnaire study. The object was to ascertain the extent to which these women may be expected to realistically estimate their own probability of contracting the disease and what influence risk perception and psychological strain have on their willingness to make use of diagnostic opportunities for early detection. Additionally, the effects on their physical and mental well-being were analyzed.

RESULTS

Among the women of the study group, a family history of breast cancer did not always correlate with the subject's perception of an increased risk of contracting the disease compared. On the whole, the majority of the women overestimated their personal risk despite prior genetic counseling. Only slightly less than one quarter of the study group correctly estimated their risk; another quarter underestimated it. The majority of those women who exhibited an increased risk perception were also those who overestimated their probability of personally contracting the disease. They underwent recommended screening examinations significantly less often than women with a low risk perception. However, women subjected to intense psychological strain showed above-average participation in screening programs.

CONCLUSIONS

Women with a family history of breast cancer often find it difficult to realistically estimate their own risk of contracting the disease. Increased risk perception had a negative effect on participation in recommended breast cancer screening. Therefore, an effort should be made to correct the patient's overestimation of her personal risk. Integrating psychological counseling in screening programs is essential considering that women from high-risk groups are subjected to increased psychological strain. Further studies are required to more precisely evaluate other psychosocial factors in the behavior of women in risk group toward screening.