The absolute structure of ptilosarcenone 2.5-hydrate, a diterpenoid briarane from the orange sea pen Ptilosarcus gurneyi (Gray).

In the title compound, C(24)H(29)ClO(8)·2.5H(2)O, which contains two organic mol-ecules (A and B) and five heavily disordered water mol-ecules in the asymmetric unit, the γ-lactone ring and the cyclo-hexenone ring are both trans-fused to the central cyclo-decene ring. The cyclehexenone ring features an α,β-unsaturated ketone with torsion angles between the conjugated carbonyl and alkene bonds of 0.

Energetics and structural consequences of axial ligand coordination in nonplanar nickel porphyrins.

The effects of ruffling on the axial ligation properties of a series of nickel(II) tetra(alkyl)porphyrins have been investigated with UV-visible absorption spectroscopy, resonance Raman spectroscopy, X-ray crystallography, classical molecular mechanics calculations, and normal-coordinate structural decomposition analysis. For the modestly nonplanar porphyrins, porphyrin ruffling is found to cause a decrease in binding affinity for pyrrolidine and piperidine, mainly caused by a decrease in the binding constant for addition of the first axial ligand; ligand binding is completely inhibited for the more nonplanar porphyrins. The lowered affinity, resulting from the large energies required to expand the core and flatten the porphyrin to accommodate the large high-spin nickel(II) ion, has implications for nickel porphyrin-based molecular devices and the function of heme proteins and methyl-coenzyme M reductase.

Photoinduced axial ligation and deligation dynamics of nonplanar nickel dodecaarylporphyrins.

The ground- and excited-state metal-ligand dynamics of nonplanar nickel(II) 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrin (NiDPP) and two fluorinated analogues (NiF(20)DPP and NiF(28)DPP) have been investigated using static and time-resolved absorption spectroscopy in toluene and in ligating media that differ in basicity, aromaticity, and steric encumbrance. Because of the electronic and steric consequences of nonplanarity, NiDPP does not bind axial ligands in the ground state, but metal coordination does occur after photoexcitation with multistep dynamics that depend on the properties of the ligand. Following the structural relaxations that occur in all nickel porphyrins within approximately 10 ps, ligand binding to photoexcited NiDPP is progressively longer in pyridine, piperidine, and 3,5-lutidine (25-100 ps) but does not occur at all in 2,6-lutidine in which the ligating nitrogen is sterically encumbered.

Synthesis, toxicity and biodistribution of two 5,15-di[3,5-(nido-carboranylmethyl)phenyl]porphyrins in EMT-6 tumor bearing mice.

The total synthesis of a 5,15-di[3,5-(o-carboranylmethyl)phenyl]porphyrin 5, its zinc(II) complex 6, and the corresponding nido-carboranylporphyrins 7 and 8 are reported. The molecular structures of porphyrin 6 and of potassium nido-carborane were obtained and are described. The biodistribution of nido-carboranylporphyrins 7 and 8 in BALB/c mice bearing EMT-6 mammary tumors are presented and compared.

Unusual aryl-porphyrin rotational barriers in peripherally crowded porphyrins.

Previous studies of 5,10,15,20-tetraarylporphyrins have shown that the barrier for meso aryl-porphyrin rotation (DeltaG++(ROT)) varies as a function of the core substituent M and is lower for a small metal (M = Ni) compared to a large metal (M = Zn) and for a dication (M = 4H(2+)) versus a free base porphyrin (M = 2H). This has been attributed to changes in the nonplanar distortion of the porphyrin ring and the deformability of the macrocycle caused by the core substituent. In the present work, X-ray crystallography, molecular mechanics (MM) calculations, and variable temperature (VT) (1)H NMR spectroscopy are used to examine the relationship between the aryl-porphyrin rotational barrier and the core substituent M in some novel 2,3,5,7,8,10,12,13,15,17,18,20-dodecaarylporphyrins (DArPs), and specifically in some 5,10,15,20-tetraaryl-2,3,7,8,12,13,17,18-octaphenylporphyrins (TArOPPs), where steric crowding of the peripheral groups always results in a very nonplanar macrocycle.

Conformational landscape surfing induced by off-on pi-pi stacking in a porphyrin-quinone dyad.

A covalently linked porphyrin-quinone dyad crystallizes with two orientations of the quinone, extended away from (off) and cofacial with the porphyrin macrocycle (on), which induce different conformations of the macrocycle and model the recently proposed structural effect of a nearby residue on the heme prosthetic group of a nitric oxide synthase.

Influence of electronic and structural effects on the oxidative behavior of nickel porphyrins.

With the aim of better understanding the electronic and structural factors which govern electron-transfer processes in porphyrins, the electrochemistry of 29 nickel(II) porphyrins has been examined in dichloromethane containing either 0.1 M tetra-n-butylammonium perchlorate (TBAP) or tetra-n-butylammonium hexafluorophosphate (TBAPF(6)) as supporting electrolyte. Half-wave potentials for the first oxidation and first reduction are only weakly dependent on the supporting electrolyte, but E(1/2) for the second oxidation varies considerably with the type of supporting electrolyte.

Synthesis, dark toxicity and induction of in vitro DNA photodamage by a tetra(4-nido-carboranylphenyl)porphyrin.

The total synthesis of tetra(4-carboranylphenyl)porphyrins 4 and 6 and their zinc(II) complexes 5 and 7 are described. These compounds were characterized by analytical and spectroscopic methods and, in the case of 5, by X-ray crystallography. The water-soluble nido-carboranylporphyrins 6 and 7 were found to have low dark toxicity towards V79 hamster lung fibroblast cells, using a clonogenic assay (50% colony survival, CS(50)>300 microM).

A novel synthetic route to fused propenochlorin and benzochlorin photodynamic therapy probes.

Reaction of meso-(2-formylvinyl)octaethylporphyrin with (CH3)3SiCN-Cu(OTf)2 produced unexpected 10(3)-trimethylsiloxyl and 10(3)-hydroxyl fused propenochlorins which, in H2SO4, underwent subsequent migration of the 8-ethyl group to the 10(3)-position of the exocyclic benzene ring to form a novel benzochlorin.

Effectiveness of a stand-alone aftercare program for drug-involved offenders.

A study was made of the effectiveness of an aftercare program operating in conjunction with area outpatient drug free treatment programs while organizationally independent of those programs. Parolees and probationers mandated to treatment were assigned to aftercare on the basis of residence in the catchment areas in which aftercare facilities were located (n = 32) and randomly to aftercare (n = 62) and control (n = 51) when not a resident in a catchment area. No outcome differences were found between aftercare groups based on proximity to facility.

Factors associated with frequent and infrequent HIV testing.

Drug user treatment clients with 5 or more HIV tests (frequent testees N=43) and 0-2 HIV tests (infrequent testees-N = 56) were compared on demographic characteristics, risk behaviors, perceived risk of HIV infection to self, involvement with family members, and psychological functioning. Extreme groups of HIV testees did not differ on any variables other than an index of perceived vulnerability to HIV infection (e.g.

Synthesis and Electrochemical Studies of a Series of Fluorinated Dodecaphenylporphyrins.

Dodecaphenylporphyrins with varying degrees of fluorination of the peripheral phenyl rings (F(x)()DPPs) were synthesized as model compounds for studying electronic effects in nonplanar porphyrins, and detailed electrochemical studies of the chloroiron(III) complexes of these compounds were undertaken. The series of porphyrins, represented as FeDPPCl and as FeF(x)()DPPCl where x = 4, 8 (two isomers), 12, 20, 28, or 36, could be reversibly oxidized by two successive one-electron transfer steps in dichloromethane to give pi-cation radicals and pi-dications, respectively. All of the compounds investigated could also be reduced by three electrons in benzonitrile or pyridine.

Synthesis and Characterization of a Series of Monometallo-, Bimetallo-, and Heterobimetallo-1,2-Ethene-Linked Cofacial Bisporphyrins.

The stepwise synthesis and characterization of a family of selectively metalated 1,2-bis[5-(2,3,7,8,12,13,17,18-octaethylporphyrinyl)]ethenes is described. These compounds are distinct from most of the previously reported bisporphyrin systems which possessed rigid linking groups or multiple strapping units, and their syntheses offer several advantages over the previously prepared systems. Among the members of this family we report the first heterobimetallic bisporphyrins able to exist as either cis (cofacial) or trans (extended) isomers including cis 13 {[Ni(II)][Zn(II)]}, cis 14{[Ni(II)][Cu(II)]}, and trans 15{[Cu(II)][Mn(III)]}.

Preparation, characterization, and luminescence properties of gallium-metal face-to-face diporphyrins (M = H(2), GaL, Ru(CO)(OH), Co).

The preparation and characterization of a new series of mixed metal cofacial anthracene-bridged diporphyrins (DPA) containing a GaL fragment (L = OMe, OH) and another metallic center (M = GaL, Ru(CO)(OH), Co, and H(2) (i.e. free base)) are reported.

Factors associated with frequency of 12-Step attendance by drug abuse clients.

Comparison was made of treatment clients attending Narcotics Anonymous and/or Alcoholics Anonymous meetings less than weekly (n = 41) with treatment clients attending meetings at least three times a week (n = 30). The frequent attenders (attending an average of 30.6 meetings monthly) differed from non- and infrequent attenders (attending an average of 0.

A complementary perspective to primary socialization theory.

Primary socialization theory as formulated by Oetting and his associates emphasizes the transmission of societal norms during childhood and adolescence within society's three major socializing agencies: family, school, and small, intimate peer groups. The norms thus transmitted may be prosocial or deviant, with prosocial norms more likely to be transmitted through strong bonds to healthy families or schools. Personality traits and other personal characteristics influence negative outcomes, such as deviance or drug use, only to the extent that they interfere with socialization to family or school.

Early deviance and related risk factors in the children of narcotic addicts.

This descriptive study examines the self-reported behaviors of 285 male and female adolescent children (ages 12-17) of narcotic addicts participating in methadone maintenance programs. These children responded to an extensive 2.5-hour interview questionnaire focusing on current and past activities, including criminal activities prior to age 12.

Differential contributions of family and peer factors to the etiology of narcotic addiction.

This retrospective study investigated relationships among early family circumstances, peer associations, and narcotic addiction in a sample of 601 urban males. Results of logistic regression analyses indicated that the extent of deviant behavior among close friends at ages 12-14 and disruption in family structure (parental divorce/separation) prior to age 11 were significantly associated with narcotic addiction. Additional regression analyses indicated that deviant behavior among family members, as well as family disruption, experienced prior to age 11, also increased the probability of association with deviant peers and a negative home atmosphere at ages 12-14.

A long-term program of research on drug use and crime.

This paper describes the major findings emanating from a long-term research program conducted in Baltimore, Maryland, on the drugs-crime relationship. It is the compilation of experiences, studies, and findings related to the research career of David N. Nurco, D.

The family experiences of narcotic addicts and their subsequent parenting practices.

This survey study of male and female narcotic addicts participating in methadone maintenance programs examined self-reported retrospective data on parental behavior experienced by addicts during their adolescent years. These findings were contrasted with the addicts' self-report of their current parenting practices with their own adolescent children. Results showed addicts as perceiving their mothers as significantly more functional in their parenting practices than their fathers on indices of parental involvement, attachment, and responsibility.

The early emergence of narcotic addict types.

Providing retrospective self-reports of their activities, perceptions, and experiences during their early adolescent years (ages 12 to 14), 255 narcotic addicts were classified into four distinct types on the basis of a clustering technique applied to risk factor information derived from five major descriptive domains: family; peer deviance; personal deviance; psychological status; and protective factors. Differentiations among the types largely involved the extent of early drug and other behavioral deviance and family dysfunction. The predictive utility of the typology was examined in terms of outcome over the first ten years of the addiction career, including age at first narcotic addiction, amount of time incarcerated, and percentage of time addicted while in the community.

Early family adversity as a precursor to narcotic addiction.

This retrospective study examined differences among three groups of urban males in the prevalence of various family risk factors occurring before age 11 and their independent contributions to subsequent deviance. The groups included: narcotic addicts; never-addicted peer controls who were associates of the addicts at age 11; and never-addicted community controls not associated with the addicts. Sixty-four percent of the addicts, compared to slightly under 40% of both control groups, reportedly experienced one or more family risk factors involving deviant behavior among family members and family disruption before age 11.

Perceptions of social pathology in the neighborhood and the etiology of narcotic addiction. A retrospective study.

In this study, we examined whether differential perceptions of poor urban neighborhoods may contribute to narcotic addiction in individuals who grow up in these neighborhoods. Three groups of adult males provided retrospective perceptions of the neighborhoods where they lived at ages 12 to 14. The groups, matched on neighborhood, age, and race, were: narcotic addicts, peer controls--a never-addicted control sample of age-11 associates of the addicts, and community controls--a never-addicted control sample of age-11 peers who did not associate with the addicts.