The Merrifield-Simmons index of a graph is defined as the total number of the independent sets of the graph and the Hosoya index of a graph is defined as the total number of the matchings of the graph. In this paper, we give formula for Merrifield-Simmons and Hosoya indices of some classes of cartesian product of two graphs K{_2}×H, where H is a path graph P{_n}, cyclic graph C{_n}, or star gra...

‎in this paper we give a characterization for all commutative‎ ‎rings with $1$ whose zero-divisor graphs are $c_4$-free.‎

Synthesis Reaction of 1a,b with 2-aminothiophenol and sodium ethanolate in ethanol does not give the expected tetracyclic ring systems, but surprisingly the spirocompounds 2 are obtained. A [2+4] cycloaddition of the intermediately formed 1,2-benzoquinone-2-imine-1-thione with the aurone was postulated. Under these conditions the thioaurones 1c,d showed no reaction. After reaction of 1with 2-am...

Antidepressant drugs have been in extensive use for over 20 years. Initially 2 groups of compounds, the monoamine oxidase inhibitors (MAOI) and tricyclic compounds based on the imipramine configuration were widely used. In the early 1960's after a few years ofwide use, interest in the MAOI group fell following the recognition of a serious adverse effect. Blackwell (1963) described the occurrenc...

Novel Cu(II) complexes CuLCl(2) (L = 1-4) have been synthesized containing the metal bound to a well-known type of tetracyclic bisaminal formed from the condensation of glyoxal and tetraazamacrocycles (1 = cyclam-glyoxal condensate, 2 = [13]aneN4-glyoxal condensate, 3 = cyclen-glyoxal condensate, 4 = isocyclam-glyoxal condensate). The four-coordinate complexes were characterized by X-ray crysta...