Research on face recognition: The Aberdeen influence.

The review of 'Recognizing faces' by Hadyn Ellis, published in the British Journal of Psychology in 1975, marked the genesis of a distinct field of research. This seminal review sprang from a broader programme of research on face recognition conducted at the University of Aberdeen, whose influence continues to be felt in what has become an internationally important research area. We discuss the background to the Aberdeen research, summarize some of its achievements, and offer reasons why it proved so successful. These reasons include the synergy between theory and practice-based studies, the value of combining different perspectives and sources of evidence, sound techniques that led to easily reproducible findings, and the emphasis on testing even the most 'common sense' assumptions.

Ligand-field excited states of hexacyanochromate and hexacyanocobaltate as sensitisers for near-infrared luminescence from Nd(iii) and Yb(iii) in cyanide-bridged d-f assemblies.

Crystallisation of [Co(CN)(6)](3-) or [Cr(CN)(6)](3-) with Ln(iii) salts (Ln = Nd, Gd, Yb) from aqueous dmf afforded the cyanide-bridged d/f systems [Ln(dmf)(4)(H(2)O)(3)(micro-CN)Co(CN)(5)] (-, discrete dinuclear species) and {[Cr(CN)(4)(micro-CN)(2)Ln(H(2)O)(2)(dmf)(4)]}(infinity) (-, infinite cyanide-bridged chains with alternating Cr and Ln centres). With Ln = Gd the characteristic long-lived phosphorescence from d-d excited states of the [M(CN)(6)](3-) units was apparent in the red region of the spectrum, with lifetimes of the order of 1 micros, since the heavy atom effect of the Gd(iii) promotes inter-system crossing at the [M(CN)(6)](3-) units to generate the phosphorescent spin-forbidden excited states. With Ln = Yb or Nd however, the d-block luminescence was completely quenched due to fast (>10(8) s(-1)) energy-transfer to the Ln(iii) centre, resulting in the characteristic sensitised emission from Yb(iii) and Nd(iii) in the near-IR region. For both - and -, calculations based on spectroscopic overlap between emission of the donor (Co) and absorption of the acceptor (Ln) suggest that the Dexter energy-transfer mechanism is responsible for the complete quenching that we observe.

New members of the [Ru(diimine)(CN)(4)](2-) family: structural, electrochemical and photophysical properties.

A series of complexes of the type K(2)[Ru(NN)(CN)(4)] has been prepared, in which NN is a diimine ligand, and were investigated for both their structural and photophysical properties. The ligands used (and the abbreviations for the resulting complexes) are 3-(2-pyridyl)pyrazole (Ru-pypz), 2,2'-bipyrimidine (Ru-bpym), 5,5'-dimethyl-2,2'-bipyridine (Ru-dmb), 1-ethyl-2-(2-pyridyl)benzimidazole (Ru-pbe), bidentate 2,2':6',2'''-terpyridine (Ru-tpy). The known complexes with = 2,2'-bipyridine (Ru-bpy) and 1,10-phenathroline (Ru-phen) were also included in this work. A series of crystallographic studies showed that the [Ru(NN)(CN)(4)](2-) complex anions form a range of elaborate coordination networks when crystallised with either K(+) or Ln(3+) cations. The K(+) salts are characterised by a combination of near-linear Ru-CN-K bridges, with the cyanides coordinating to K(+) in the usual 'end-on' mode, and unusual side-on pi-type coordination of cyanide ligands to K(+) ions. With Ln(3+) cations in contrast only Ru-CN-Ln near-linear bridges occurred, affording 1-dimensional helical or diamondoid chains, and 2-dimensional sheets constituted from linked metallamacrocyclic rings. All of the K(2)[Ru(CN)(4)] complexes show a reversible Ru(II)/Ru(III) couple (ca.+0.9 V vs. Ag/AgCl in water), the exception being Ru-tpy whose oxidation is completely irreversible. Luminescence studies in water showed the presence of (3)MLCT-based emission in all cases apart from Ru-bpym with lifetimes of tens/hundreds of nanoseconds. Time-resolved infrared studies showed that in the (3)MLCT excited state the principal C-N stretching vibration shifts to positive energy by ca. 50 cm(-1) as a consequence of the transient oxidation of the metal centre to Ru(III) and the reduction in back-bonding to the cyanide ligands; measurement of transient decay rates allowed measurements of (3)MLCT lifetimes for those complexes which could not be characterised by luminescence spectroscopy. A few complexes were also examined in different solvents (MeCN, dmf) and showed much weaker emission and shorter excited-state lifetimes in these solvents compared to water.

Dichlorotetrakis[3-(4-pyridyl)-1H-pyrazole]cobalt(II) acetonitrile tetrasolvate: an infinite hydrogen-bonded network, in an instant.

Reaction of 3-(4-pyridyl)pyrazole (4pypz) with cobalt(II) chloride in acetonitrile affords the title complex, [CoCl(2)(C(8)H(7)N(3))(4)].4CH(3)CN, within seconds of addition, as purple X-ray quality crystals. The molecule has C4 symmetry. The metal ion exhibits a trans-N(4)Cl(2) octahedral geometry, with the four 3-(4-pyridyl)-1H-pyrazole ligands coordinating through their pyridyl N-atom donors; one coordinated chloride ion forms hydrogen bonds with the pyrazole rings from four separate units. This configuration creates an infinite three-dimensional coordination network containing channels that are filled with acetonitrile solvent molecules.

Photophysical properties of Pr(III) and Er(III) complexes of poly(pyrazolyl)borates.

The complexes [M(L(1))(2)(NO(3))] and [M(L(2))(NO(3))(2)](M = Pr, Er; L(1)= the tetradentate ligand dihydrobis-[3-(2-pyridyl)pyrazolyl]borate; L(2)= the hexadentate ligand hydrotris-[3-(2-pyridyl)pyrazolyl]borate) were prepared and their structural and photophysical properties studied. All complexes are 10-coordinate. Crystallographic analysis of [M(L(1))(2)(NO(3))](M = Pr, Er) showed that for the smaller Er(iii) ions steric congestion at the metal centre results in two of the Er-N(pyridyl) distances being particularly long, which does not occur with the larger Pr(iii) ion that is better able to accommodate 10-fold coordination. On UV irradiation, both Pr(iii) complexes show, in the visible region of their luminescence spectra, transitions originating from both the (3)P(0) level (at ca. 21,000 cm(-1)) and the (1)D(2) level (at ca. 17,000 cm(-1)), a consequence of the fact that the lowest triplet state of the coordinated pyrazolylborate ligands lies at ca. 24,000 cm(-1) in each case so is high enough in energy to populate both levels. This contrasts with Pr(iii) complexes based on diketonate ligands in which the lower triplet energies of the ligands result in emission from the (1)D(2) level only. At longer wavelengths, near-infrared luminescence arising from the (1)D(2) emissive level is observed with lifetimes (in both the solid state and solution) being in the range 50-110 ns. For both Er(iii) complexes, luminescence at 1530 nm occurs following UV excitation of ligand-centred transitions. In CH(2)Cl(2) both complexes gave dual-exponential luminescence, with the major component having a lifetime characteristic of an intact Er(iii) complex (approximately 1.5 micros) and the minor component being much shorter lived (0.2-0.5 micros), suggestive of a species in which a ligand is partially detached and the metal is solvated, with the two forms interconverting slowly. This behaviour is consistent with the steric congestion and long M-N(pyridyl) bonds that were observed in [Er(L(1))(2)(NO(3))]. In the solid state both Er(iii) complexes gave very weak luminescence, which could be fitted to a single exponential decay with a lifetime similar to the longer-lived of the solution components.

Structural and photophysical properties of coordination networks combining [Ru(bipy)(CN)4]2- anions and lanthanide(III) cations: rates of photoinduced Ru-to-lanthanide energy transfer and sensitized near-infrared luminescence.

Co-crystallization of K2[Ru(bipy)(CN)4] with lanthanide(III) salts (Ln = Pr, Nd, Gd, Er, Yb) from aqueous solution affords coordination oligomers and networks in which the [Ru(bipy)(CN)4]2- unit is connected to the lanthanide cation via Ru-CN-Ln bridges. The complexes fall into two structural types: [{Ru(bipy)(CN)4}2{Ln(H2O)m}{K(H2O)n}] x xH2O (Ln = Pr, Er, Yb; m = 7, 6, 6, respectively), in which two [Ru(bipy)(CN)4]2- units are connected to a single lanthanide ion by single cyanide bridges to give discrete trinuclear fragments, and [{Ru(bipy)(CN)4}3{Ln(H2O)4}2] x xH2O (Ln = Nd, Gd), which contain two-dimensional sheets of interconnected, cyanide-bridged Ru2Ln2 squares. In the Ru-Gd system, the [Ru(bipy)(CN)4]2- unit shows the characteristic intense (3)metal-to-ligand charge transfer luminescence at 580 nm with tau = 550 ns; with the other lanthanides, the intensity and lifetime of this luminescence are diminished because of a Ru --> Ln photoinduced energy transfer to low-lying emissive states of the lanthanide ions, resulting in sensitized near-infrared luminescence in every case. From the degree of quenching of the Ru-based emission, Ru --> Ln energy-transfer rates can be estimated, which are in the order Yb (k(EnT) approximately 3 x 10(6) sec(-1), the slowest energy transfer) < Er < Pr < Nd (k(EnT) approximately 2 x 10(8) sec(-1), the fastest energy transfer). This order may be rationalized on the basis of the availability of excited f-f levels on the lanthanide ions at energies that overlap with the Ru-based emission spectrum. In every case, the lifetime of the lanthanide-based luminescence is short (tens/hundreds of nanoseconds, instead of the more usual microseconds), even when the water ligands on the lanthanide ions are replaced by D2O to eliminate the quenching effects of OH oscillators; we tentatively ascribe this quenching effect to the cyanide ligands.

New bis-, tris- and tetrakis(pyrazolyl)borate ligands with 3-pyridyl and 4-pyridyl substituents: synthesis and coordination chemistry.

The new ligands dihydrobis[3-(4-pyridyl)pyrazol-1-yl]borate [Bp(4py)]-, hydrotris[3-(4-pyridyl)pyrazol-1-yl]borate [Tp(4py)]-, tetrakis[3-(4-pyridyl)pyrazol-1-yl]borate [Tkp(4py)]-, dihydrobis[3-(3-pyridyl)pyrazol-1-yl]borate [Bp(3py)]-, hydrotris[3-(3-pyridyl)pyrazol-1-yl]borate [Tp(3py)]- and tetrakis[3-(3-pyridyl)pyrazol-1-yl]borate [Tkp(4py)]- are derivatives of the well known bis-, tris- and tetrakis-(pyrazolyl)borate cores, bearing 4-pyridyl or 3-pyridyl substituents attached to the pyrazolyl C3 positions. These pyridyl groups cannot chelate to the metal ions in the poly(pyrazolyl) cavity but are externally directed. Structural studies on a range of metal complexes show how, in many cases, coordination of these pendant pyridyl groups to the M(pyrazolyl)n core of an adjacent metal complex fragment results in formation of coordination oligomers or polymeric networks. [Tl(Bp(3py))], [Tl(Bp(4py))] and [Tl(Tp(4py))] form one-dimensional polymeric chains via coordination of one of their pendant pyridyl units to the Tl(I) centre of an adjacent complex fragment; in contrast, in [Tl(Tp(3py))] coordination of all three pendant pyridyl units to separate Tl(I) neighbours results in formation of a two-dimensional polymeric sheet. In [Tl(Tkp(3py))] and [Tl(Tkp(4py))] the Tl(I) is coordinated by two or three of the four pyrazolyl arms, respectively; bridging interactions of pendant 4-pyridyl groups with adjacent Tl(I) centres result in a two-dimensional sheet forming in each case. In Ag(Tkp(4py)) each Ag(I) ion is coordinated by two pyrazolyl rings, and two bridging pyridyl ligands from other complex units, resulting in a one-dimensional chain consisting of pairs of cross-linked zigzag chains. In contrast to these polymeric coordination networks, the structures of [Cu(Tp(4py))] and [(Tp(3py))Cd(CH3CO2)] are dimers, with a pendant pyridyl residue from the first metal centre attaching to a vacant coordination site on the second, and vice versa; these dimers are stabilised by pi-stacking interactions between sections of the two ligands. [Ni(Tp(3py))2] is monomeric, with an octahedral coordination geometry arising from two tris(pyrazolyl)borate chelates; the array of pendant 3-pyridyl groups is involved only in intramolecular hydrogen-bonding. [(Tp(4py))Re(CO)3] is also monomeric, with a facial arrangement of three pyrazolyl ligands and three carbonyls, with the pendant 4-pyridyl groups not further coordinated. [(Tp(2py))Re(CO)3], based on the related ligand hydrotris[3-(2-pyridyl)pyrazol-1-yl]borate, has a similar fac-(CO)3(pyrazolyl)3 coordination geometry.

Bis(1,3-diphenylpropane-1,3-dionato-kappa2O,O'){hydrotris[3-(2-pyridyl)pyrazol-1-yl]borato}praseodymium(III): another member of an unpredictable series.

Reaction of praseodymium(III) chloride with stoichometric quantities of dibenzoylmethane (Hdbm) and hydrotris[3-(2-pyridyl)pyrazol-1-yl]borate (Tp 2py) affords the title complex, [Pr(C24H19BN9)(C15H11O4)2]. The lanthanide ion in this ternary complex exhibits an N6O4 ten-coordinate geometry arising from the five bidentate arms found on the anionic ligands. The structure is entirely different from those found in other lanthanide complexes with the same ligand set.

Structural and near-IR photophysical studies on ternary lanthanide complexes containing poly(pyrazolyl)borate and 1,3-diketonate ligands.

The ligands tris[3-(2-pyridyl)pyrazol-1-yl]hydroborate (L1, potentially hexadentate) and bis[3-(2-pyridyl)pyrazol-1-yl]dihydroborate (L2, potentially tetradentate) have been used to prepare ternary lanthanide complexes in which the remaining ligands are dibenzoylmethane anions (dbm). [Eu(L1)(dbm)2] is eight-coordinate, with L1 acting only as a tetradentate chelate (with one potentially bidentate arm pendant) and two bidentate dbm ligands. [Nd(L1)(dbm)2] was also prepared but on recrystallization some of it rearranged to [Nd(L1)2][Nd(dbm)4], which contains a twelve-coordinate [Nd(L1)2]+ cation (two interleaved hexadentate podand ligands) and the eight-coordinate anion [Nd(dbm)4]- which, uniquely amongst eight-coordinate complexes having four diketonate ligands, has a square prismatic structure with near-perfect O8 cubic coordination. Formation of this sterically unfavourable geometry is assumed to arise from favourable packing with the pseudo-spherical cation. The isostructural series of complexes [Ln(L2)(dbm)2](Ln = Pr, Nd, Eu, Gd, Tb, Er, Yb) was also prepared and all members structurally characterised; again the metal ions are eight-coordinate, from one tetradentate ligand L2 and two bidentate dbm ligands. Photophysical studies on the complexes with Ln = Pr, Nd, Er, and Yb were carried out; all show the near-IR luminescence characteristic of these metal ions, with longer lifetimes in CD3OD than in CH3OH. For [Yb(L2)(dbm)2], two species with different luminescence lifetimes were observed in CH3OH solution, corresponding to species with zero or one coordinated solvent molecules, in slow exchange on the luminescence timescale. For [Nd(L2)(dbm)2] a single average solvation number of 0.7 was observed in MeOH. For [Pr(L2)(dbm)2] a range of emission lines in the visible and NIR regions was detected; time-resolved measurements show a particularly high susceptibility to quenching by solvent CH and OH oscillators.

Stalking: knowns and unknowns.

The current work reviews literature on the nature of stalking. Despite its nebulous nature and differing legal and clinical definitions of stalking, researchers and practitioners are referring to the same phenomenon. Stalking is chronic, consisting of a number of nuisance behaviors that appear consistent over countries and samples. Different categorizations of stalkers and their victims exist, but ex-partner stalkers are a distinctive category with respect to their prevalence, violence risk, and attrition rate. Different samples and definitions and false victimization reports obscure reliable lifetime prevalence estimates, but these appear to be around 12%-16% among women and 4%-7% among men. Stalking has deleterious effects on victims but some of the effects may be the result of stalking's exacerbating of existing vulnerabilities. Future research should focus on subgroups of stalkers and their victims, on cross-cultural investigations, and on the co-occurrence of stalking with other crimes.

'There's no smoke without fire': are male ex-partners perceived as more 'entitled' to stalk than acquaintance or stranger stalkers?

In a stalking scenario, the prior relationship between and the gender of stalker and victim were systematically manipulated in order to judge culpability and consequences for the persons involved. Written vignettes were presented to 168 participants who responded via seven Likert scales. Stalker-victim relationship had three levels: ex-partner, acquaintance and stranger. In accordance with the 'Just World' hypothesis (Lerner, 1980), the victim was judged as having greater responsibility for the stalking when their harasser was an ex-partner or a prior acquaintance rather than a stranger, and police intervention was felt to be most necessary when the stalker was a stranger. Sex of stalker and victim was manipulated, and the following comparisons proved significant: when the perpetrator was male, bodily injury to the victim was seen as more likely and police intervention as more necessary than when the perpetrator was female; and male victims were viewed as more responsible for the scenario and as possessing greater powers to alleviate it. The Just World hypothesis and gender stereotypes provide a plausible account for these findings. Future research should determine whether criminal convictions show similar biases towards convicting male and stranger stalkers more often than female and ex-partner stalkers.

Violence and the prior victim-stalker relationship.

INTRODUCTION: Previous research has suggested that stalkers who are ex-partners are more likely to be violent towards their victims than acquaintance or stranger stalkers. A survey was conducted in Britain of 95 individuals who had contacted the Suzy Lamplugh Trust because they were being stalked. METHOD: Eighty-seven of the victims were female and seven were male. They were put into three categories: ex-intimates, former acquaintances and strangers. RESULTS: Ex-intimates were the most aggressive of the three groups. Ex-partners were overall the most intrusive in their behaviour and were also the most likely to threaten and assault third parties as well as their principal victim. Stranger stalkers, however, were significantly more likely than ex-partners to be convicted of stalking-related offences. CONCLUSION: The experiences of our sample would suggest that being stalked carries a high violence risk. Across relational subtypes, over 40% of respondents had experienced physical assault, including attempted murder, sexual assault, or a combination of these acts.