Enthalpy of solution, ΔHsolo
, enthalpy of sublimation, ΔHsublo
, apparent partial molar volume and heat capacities,V2o
were determined for aqueous solutions of thirty alkylated derivatives of uracyl and adenine, eight derivatives of cytosine
and guanine. Calculated accessible surface areas and molar volumes are presented, too. The values of enthalpy of solution,
enthalpy of sublimation can be useful in the studies on the nature of interaction between these compounds and water molecules.
Apparent partial molar volume and heat capacity give a new aspect on hydrophob properties of the examined nucleic acid base
Wojciech Zielenkiewicz was born in Warsaw on 6 June 1933. He studied chemistry
at the Warsaw University and graduated in 1955. His master thesis in the field
of nuclear chemistry dealt with the enrichment of bromobenzene by the Szilard-Chalmers
method. Since 1955 his professional career has mostly been related to the
Institute of Physical Chemistry of the Polish Academy of Sciences (PAS) founded
in the same year.
Wojciech Zielenkiewicz worked under the supervision of Prof. Wojciech Świętosławski.
This cooperation had a powerful influence on Zielenkiewicz both as a researcher
and as a person. His strong interest in thermochemistry at that time resulted
partly from his research interest and partly from his attraction to one of
the students doing her diploma who later became his wife. Zielenkiewicz’s
PhD thesis carried out under Świętosławski’s supervision
concerned the thermochemistry of cement hydration. For the purposes of this
work, Zielenkiewicz constructed his first calorimeter – a labyrinth
flow calorimeter which was a modified version of the first such calorimeter
constructed by Świętosławski and Malawski in 1935. The calorimeter
was applied for the determination of the heat of cement hardening.
After his PhD, Zielenkiewicz
worked on several other calorimeters for the study of heat of cement hydration
with the quasi-adiabatic method as well as on ‘conduction’ calorimeters
for the examination of the first phase of cement hydration. This activity
resulted in a monograph Calorimetry and Thermochemistry of Cement written
in collaboration with T. Krupa and published in 1975.
In the following years, his scientific interests
were focused mostly on various aspects of the transfer of heat energy in time,
i.e. thermokinetics. He constructed a number of calorimeters for this type
of measurements and, together with his co-workers, elaborated new numerical
methods of determination of thermokinetics. Those methods were assessed at
international symposia on thermokinetics organised by Zielenkiewicz in cooperation
with the French Association of Calorimetry and Thermal Analysis (AFCAT). In
this period, he established regular cooperation with scientists from France,
Spain, and the USA. Research on thermokinetics includes not only theoretical
studies but also experimental works. Most of the experiments conducted at
the Department of Calorimetry headed by Prof. Zielenkiewicz were connected
with inclusion compounds, particularly Werner complexes as well as porfyrine
the last twenty years, Zielenkiewicz conducted research in the scope of biomolecules.
The study resulted in the determination of thermodynamic properties of over
60 derivatives of nucleic acid bases and the establishment of new correlations
between enthalpic, volume, and structural properties of the compounds examined.
His most recent interests concerned the study of enthalpic processes of protein
long and intensive work in the field of calorimetry and thermokinetics has
appeared in numerous books and publications presenting his research results.
He is the author of 7 monographs, a number of chapters in a monograph and
about 200 scientific publications. They include, among others, Analysis of
Course of Heat Effect in n-n Calorimeters, Signal Processing of Calorimetric
System, Dynamic Theory (later translated into Russian and published in Russia),
Advances in Calorimetry and Thermochemistry, Theory of Calorimetry written
together with E. Margas and published in 2002 by Kluwer and the most recent
book, Calorimetry, published in 2005.
Prof. Zielenkiewicz has also been active as a supervisor.
He assisted and supported the realisation of 14 completed PhD theses of the
employees at the Institute of Physical Chemistry and is supervising 3 more
students of the Institute. Moreover, he has been involved in the realization
of several more PhD theses both in Poland and abroad.
For many years Prof. Zielenkiewicz combined his activity
on research with research coordination. He managed the organizational units
of the Polish Academy of Sciences as the Director General of the PAS and as
a Deputy Scientific Secretary. For 6 years he was a Scientific Secretary of
the Division of Mathematical, Physical and Chemical Sciences of PAS. In the
years 1968–2003 he headed the Laboratory and Department of Calorimetry
and he was a director of the Institute of Physical Chemistry for 19 years.
His directorship in the Institute happened in a very difficult period for
Poland, i.e. when the Marshall Law was introduced in 1981. As numerous employees
of the Institute were involved in the illegal Solidarity movement at that
time, the position of a director of such an institution was extremely uncomfortable
and required great abilities in dealing with the communist authorities in
such a way as to protect those employees. It must be said that Prof. Zielenkiewicz
faced this challenge with success.
Prof. Zielenkiewicz was also an initiator of the
Polish conferences on calorimetry and thermal analysis. The first one was
held over 30 years ago. These conferences created an opportunity
for Polish researchers to exchange their opinions and learn about the world
research trends. Numerous outstanding scientists were guests at these conferences.
Many of them are members of the Polish Society of Calorimetry and Thermal
Zielenkiewicz has been awarded many state and foreign medals and distinctions,
among others, Wojciech Świętosł;awski’s Medal and the Calvet
Award given by the French Association of Calorimetry and Thermal Analysis
(AFCAT) as well as the most prominent Polish state orders including the Order
of Polonia Restituta (the Knight’s Cross) and the Order of Labour Banner.
He is a corresponding member of the Polish Academy of Sciences and the Royal
Academy of Sciences in Barcelona.
Dr. Paweł Gierycz