Fast atom bombardment mass spectrometry studies of ruthenium (II) polypyridy coordination complexes and of group V Triptycenes and related complexes

In order to investigate the use of Fast Atom Bombardment Mass Spectrometry (FAB-MS) as a tool for structural characterization, two groups of complexes are analyzed. The first group is a set of ruthenium(II) coordination complexes containing bidentate polypyridyl ligands. The positive and negative ion FAB-MS spectra are found to be sufficient to allow for an almost complete characterization of the central metal atom, the ligands and the counter anions contained in the intact complex. An unusual observation of mUltiply charged ions in the positive ion FAB-MS spectra (i.e. [RUL 3 ]2+) is explained to be as a result of the oxidative quenching of the excited state of the doubly charged ion by the matrix, 3-nitrobenzyl alcohol. An analysis of a mixture shows that the technique is a good one for identifying components therein. A group of triptycene and related complexes containing Group V elements is also analyzed by FAB-MS and the results. in terms of relative abundances of fragment ions, are found to be consistent with known metal-carbon bond strengths.

Families with Children with Autism, Developmental Delay, and Typical Development: The Relationships of Parenting Self-Efficacy, Parenting Strategies, and Child Problem Behaviour

Parents of children with autism spectrum disorders (ASD) and developmental delays (DD) may experience more child problem behaviours, report lower parenting selfefficacy (PSE), and be more reactive than proactive in their parenting strategies than those who have children with typical development (TD). Differences in PSE and parenting strategies may also influence the extent to which child problem behaviours are experienced by parents who have children with ASD and DD, compared to those who have children with TD. Using a convenience sample of parents of children with ASD (n = 48), DD (n = 51), and TD (n = 72), this study examined group differences on three key variables: PSE, parenting strategies, and child problem behaviour. Results indicated that those in the DD group scored lower on PSE in preventing child problem behaviour than the ASD group. The TD group used fewer reactive strategies than the DD group, and fewer proactive strategies than both the ASD and DD groups. For the overall sample, higher reactive strategies use was found to predict higher ratings of child problem behaviour, while a greater proportion of proactive to reactive strategies use predicted lower ratings of child problem behaviour. PSE was found to moderate DD diagnosis and child problem behaviour. Implications for a behavioural (i.e., parenting strategies) or cognitive (i.e., PSE) approach to parenting are discussed.

Rings, Group Rings, and Their Graphs

We associate some graphs to a ring R and we investigate the interplay between the ring-theoretic properties of R and the graph-theoretic properties of the graphs associated to R. Let Z(R) be the set of zero-divisors of R. We define an undirected graph ᴦ(R) with nonzero zero-divisors as vertices and distinct vertices x and y are adjacent if xy=0 or yx=0. We investigate the Isomorphism Problem for zero-divisor graphs of group rings RG. Let Sk denote the sphere with k handles, where k is a non-negative integer, that is, Sk is an oriented surface of genus k. The genus of a graph is the minimal integer n such that the graph can be embedded in Sn. The annihilating-ideal graph of R is defined as the graph AG(R) with the set of ideals with nonzero annihilators as vertex such that two distinct vertices I and J are adjacent if IJ=(0). We characterize Artinian rings whose annihilating-ideal graphs have finite genus. Finally, we extend the definition of the annihilating-ideal graph to non-commutative rings.