The first optical spectrum of an isolated polycyclic aromatic hydrocarbon large enough to survive the photophysical conditions of the interstellar medium is reported. Vibronic bands of the first electronic transition of the all benzenoid polycyclic aromatic hydrocarbon hexa-peri -hexabenzocoronene were observed in the 4080 − 4530 Å range by resonant 2-color 2-photon ionization spectroscopy. The...

Stereospecific synthesis and (chir)optical redox properties of helicenoid-based phosphepine as well chiral P-containing polycyclic aromatic hydrocarbons are presented.

IMPORTANCE Polycyclic aromatic hydrocarbons are widespread urban air pollutants from combustion of fossil fuel and other organic material shown previously to be neurotoxic. OBJECTIVE In a prospective cohort study, we evaluated the relationship between Attention Deficit Hyperactivity Disorder behavior problems and prenatal polycyclic aromatic hydrocarbon exposure, adjusting for postnatal expos...

The emerging mega city of Lahore has been progressing by leaps and bounds in lasttwo decades which is directly related to an immense increase number vehicles powergeneration systems using fossil fuels. present study entails the quantification evaluation ofpotential risk due Polycyclic Aromatic Hydrocarbons (PAHs) one known organicpollutants from vehicular, power generation system’s exhaust othe...

The new polycyclic borazines B(2){1,2-N(2)C(6)H(4)}(2){B(2)(NMe(2))(2)}(2), B(2){1,8-N(2)naph}(2){B(2)(NMe(2))(2)}(2) and B(2)(NPh)(4){B(2)(NMe(2))(2)}(2) have been prepared from diborate(4) anions and two equivalents of B(2)Cl(2)(NMe(2))(2) and have been structurally characterised. Aspects of their structure and bonding are discussed and comparison made with corresponding polycyclic aromatic h...

Measurements of the concentration of 3:4-benzpyrene and other polycyclic aromatic hydrocarbons have been made in gas works retort houses of several types. The tarry fumes which escaped from retorts contained extremely high concentrations of polycyclic hydrocarbons, but in general men were only exposed to these very briefly. The mean concentration of 3 :4-benzpyrene determined from long-period s...

With the goal of eventually synthesizing [5]radialene (3), the still missing member of the parent radialene hydrocarbons, we have prepared the pentaacetates 21 and 31, the pentabromide 29 and the hexabromide 32. In principle these should be convertible by elimination reactions to the desired target molecule.