Long Excited-State Lifetimes in Three-Coordinate Copper(I) Complexes via Triplet-Triplet Energy Transfer to Pyrene-Decorated Isocyanides.

There has been much effort to improve excited-state lifetimes in photosensitizers based on earth-abundant first-row transition metals. Copper(I) complexes have gained significant attention in this field, and in most cases, sterically driven approaches are used to optimize their lifetimes. This study presents a series of three-coordinate copper(I) complexes (Cu1-Cu3) where the excited-state lifetime is extended by triplet-triplet energy transfer. The heteroleptic compounds feature a cyclohexyl-substituted ß-diketiminate (CyNacNacMe) paired with aryl isocyanide ligands, giving the general formula Cu(CyNacNacMe)(CN-Ar) (CN-dmp = 2,6-dimethylphenyl isocyanide for Cu1; CN-pyr = 1-pyrenyl isocyanide for Cu2; CN-dmp-pyr = 2,6-dimethyl-4-(1-pyrenyl)phenyl isocyanide for Cu3). The nature, energies, and dynamics of the low-energy triplet excited states are assessed with a combination of photoluminescence measurements at room temperature and 77 K, ultrafast transient absorption (UFTA) spectroscopy, and DFT calculations. The complexes with the pyrene-decorated isocyanides (Cu2 and Cu3) exhibit extended excited-state lifetimes resulting from triplet-triplet energy transfer (TTET) between the short-lived charge-transfer excited state (3CT) and the long-lived pyrene-centered triplet state (3pyr). This TTET process is irreversible in Cu3, producing exclusively the 3pyr state, and in Cu2, the 3CT and 3pyr states are nearly isoenergetic, enabling reversible TTET and long-lived 3CT luminescence. The improved photophysical properties in Cu2 and Cu3 result in improvements in activity for both photocatalytic stilbene E/Z isomerization via triplet energy transfer and photoredox transformations involving hydrodebromination and C-O bond activation. These results illustrate that the extended excited-state lifetimes achieved through TTET result in newly conceived photosynthetically relevant earth-abundant transition metal complexes.

Early events in the mechanism of single-source chemical vapor deposition of zirconium and hafnium diboride: a computational investigation.

Chemical vapor deposition (CVD) of group 4 metal-diboride ceramics from a single source is a versatile technique that finds many applications from hypersonic flight to microelectronics. Though the kinetics of CVD have been studied extensively-allowing significant process improvements-a mechanistic understanding of the process has yet to be attained. Computations suggest two plausible reaction pathways-one higher-energy and the second lower-that correlate well with experimental results reported in the literature, explaining phenomena such as high-temperature deposition resulting in films overstoichiometric in boron. These insights offer a new perspective that may be instrumental in the rational design of new precursors for single-source CVD.

Enhanced Deep-Red Phosphorescence in Cyclometalated Iridium Complexes with Quinoline-Based Ancillary Ligands.

Compounds with good photoluminescence quantum yields (ΦPL) in the deep-red to near-infrared parts of the spectrum are desired for a variety of applications in optoelectronics, imaging, and sensing. However, in this region of the spectrum, quantum yields are usually modest, which is explained by the energy gap law and the inherently slower radiative decay rates for low-energy emitters according to the second-order perturbation theory. In this work, we outline a new direction in deep-red luminescence, introducing a new suite of bis-cyclometalated iridium complexes with efficient luminescence beyond 650 nm. Seven new complexes are prepared using two different cyclometalating (C^N) ligands with four quinoline-derived ancillary ligands (L^X). The chosen cyclometalating ligands are well-established to produce deep-red phosphorescence and include a metalated phenyl ring appended to a conjugated heterocycle. The ancillary ligands combine a rigid quinoline or benzoquinoline "L" donor with a variable anionic "X" donor comprised of an O-donor aryloxy or carboxylate or an N-donor amidate. These complexes phosphoresce in the deep-red region with wavelengths between 650 and 700 nm and solution quantum yields between 0.018 and 0.42.

Three-Electron Nickel(I)/Nickel(0) Half-Bond.

An (N-heterocyclic carbene)nickel(I) cation precursor reacts with the corresponding nickel(0) complex to form a dinickel(I,0) monocation. The Ni···Ni distance in this cation is 0.93 Å shorter than in the analogous dinickel(0) complex. Although the solid-state structure shows equivalent Ni centers, density functional theory calculations indicate significant electronic localization. Reactions with CO and NO form mononuclear carbonyl and nitrosyl complexes. Oxidative addition of an aryl bromide results in C-arylation of the carbene ligands.

Synthetically Tunable White-, Green-, and Yellow-Green-Light Emission in Dual-Luminescent Gold(I) Complexes Bearing a Diphenylamino-2,7-fluorenyl Moiety.

The syntheses and photophysical characterization of five new gold(I) complexes bearing diphenylamine-substituted fluorenyl moieties are reported; four are characterized by X-ray diffraction crystallography. Ancillary ligation on gold(I) is provided by organophosphine and N-heterocyclic carbene ligands. Two complexes, Au-DPA0 and Au-DPA1, are σ-aryls, two, Au-ADPA0 and Au-ADPA1, are σ-alkynyls, and one, Au-TDPA1, is a σ-triazolyl bound through carbon. All complexes show vibronically structured absorption and luminescence bands that are assignable to π-π* transitions localized on the diphenylamine-substituted fluorenyl π system. The excited-state dynamics of all five chromophores are governed by selection of the ancillary ligand and σ attachment of the diphenylamine-substituted fluorenyl moiety. All of these chromophores are dual luminescent in a toluene solution at 298 K. The luminescence from the aryl derivatives, Au-ADPA0 and Au-DPA1, appears green. The alkynyl derivative containing a phosphine ancillary ligand, Au-ADPA0, is a white-light emitter, while the alkynyl derivative containing an N-heterocyclic carbene ancillary ligand, Au-ADPA1, is a yellow-light emitter. The luminescence from the triazolyl-linked chromophore, Au-TDPA1, appears as yellow-green. Spin-restricted density functional theory calculations support the assignments of ligand-centric optical transitions but with contributions of ligand-to-metal charge transfer involving the vacant Au 6p orbital.

A systematic review of English language patient-reported outcome measures for use in urogynaecology and female pelvic medicine.

INTRODUCTION: Patient-reported outcome measures (PROMs) are widely used in clinical practice and research in urogynaecology. There is no consensus on which PROMs should be used. No unifying document identifies all available PROMs and compares the psychometric properties of these. METHODS: Systematic review of the literature following PRISMA guidelines. Studies where women had been administered an English-language PROM which assessed pelvic-floor symptomatology and psychometric properties had been reported were included. RESULTS: 85 PROMs assessing pelvic-floor symptoms in a urogynaecology population were identified. 43 PROMs assessed lower urinary tract symptoms in 95 studies, four PROMS assessed vaginal symptoms in seven studies, 20 PROMs assessed bowel symptoms in 27 studies and three PROMs assessed sexual symptoms in seven studies. 15 PROMs assessed two or more of these symptom areas in 60 studies. PROMs with the with the best available psychometric evidence within these five areas were (urinary symptoms) the Incontinence Quality-of-Life questionnaire (I-QOL aka ICIQ-UIqol) and International Consultation on Incontinence Questionnaire (ICIQ-UI-SF), (bowel symptoms) the Accidental Bowel Leakage Evaluation (ABLE) questionnaire and the International Consultation on Incontinence Bowel questionnaire (ICIQ-B), (vaginal symptoms) the Pelvic Organ Prolapse Symptom Score (POPSS), (sexual symptoms) the Pelvic organ prolapse- urinary Incontinence Sexual function Questionnaire- IUGA revised (PISQ-IR) and (comprehensive PROMs) the Australian Pelvic Floor Questionnaire and the Electronic Personal Assessment Questionnaire-Pelvic-Floor (ePAQ-PF). CONCLUSIONS: Multiple PROMs with robust psychometric properties are available. Some widely used PROMs have weak evidence. Formal recommendations on which English-language PROMs to use within clinical practice and research in urogynaecology are required.

Two-photon absorption characterization and comparison of Au(I) fluorenyl benzothiazole complexes in the visible wavelength regime.

We use the two-photon excited fluorescence method to determine the two-photon absorption (2PA) cross sections of three series of (fluorenyl benzothiazole) gold(I) complexes in the visible wavelength range from 570 to 700 nm. We compare the effect of ancillary ligand substitutions on the 2PA magnitudes and find that the ancillary ligand does not drastically affect either the magnitude or the shape of 2PA. Even so, moderate 2PA cross sections were measured that ranged from 10 to 1000 s of GM (Göppert-Mayer, =10-50cm4s/photon), making these types of complexes nonlinear optical materials for two-photon absorbing applications.

Room-Temperature Phosphorescent Platinum(II) Alkynyls with Microsecond Lifetimes Bearing a Strong-Field Pincer Ligand.

The use of organometallic triplet emitters in organic light emitting diodes (OLEDs) is motivated by the premise of efficient intersystem crossing leading to unit internal quantum efficiencies. However, since most devices are based on solid-state components, an inherent limitation to square-planar platinum(II) phosphors is their tendency toward aggregation-based quenching. Here, a new class of emissive, four-coordinate PtII species based on the bisimidazolyl carbazolide (BIMCA) ligand is introduced, which displays highly efficient, long-lived solid-state phosphorescence at room temperature. A set of four BIMCAPt phenyl acetylides were synthesized that emit in the green (λmax =507-540 nm) with >60 % quantum yield and millisecond lifetimes. The structures of the resulting species reveal a non-planar structure imposed by steric clashes between BIMCA and the iodo or alkynyl co-ligand. Ground-state and photophysical characterization are presented. Density functional theory calculations indicate that the BIMCA ligand dominates the frontier orbitals along with the first Franck-Condon singlet and triplet excited states.

Synthesis and photophysics of gold(i) alkynyls bearing a benzothiazole-2,7-fluorenyl moiety: a comparative study analyzing influence of ancillary ligand, bridging moiety, and number of metal centers on photophysical properties.

Three new gold(i) alkynyl complexes (Au-ABTF(0-2)) containing a benzothiazole fluorenyl moiety, with either an organic phosphine or N-heterocyclic carbene as ancillary ligand, have been synthesized and photophysically characterized. All three complexes display highly structured ground-state absorption and luminescence spectra. Dual-luminescence is observed in all three complexes at room temperature in toluene after three freeze-pump-thaw cycles. The phosphine complexes (Au-ABTF(0-1)) exhibit similar photophysics with fluorescent quantum yields ∼0.40, triplet-state quantum yields ∼0.50, and fluorescent lifetimes ∼300 ps. The carbene complex Au-ABTF2 displays different behavior; having a fluorescent quantum yield of 0.23, a triplet-state quantum yield of 0.61, and a fluorescent lifetime near 200 ps, demonstrating that the ancillary ligand alters excited-state dynamics. The compounds exhibit strong (on the order of 105 M-1 cm-1) and positive excited-state absorption in both their singlet and triplet excited states spanning the visible region. Delayed fluorescence resulting from triplet-triplet annihilation is also observed in freeze-pump-thaw deaerated samples of all the complexes in toluene. DFT calculations (both static and time-resolved) agree with the photophysical data where phosphine complexes have slightly larger S1-T2 energy gaps (0.28 eV and 0.26 eV) relative to the carbene complex (0.21 eV). Comparison of the photophysical properties of Au-ABTF(0-2) to previously published dinuclear gold(i) complexes and mononuclear gold(i) aryl complexes bearing the same benzothiazole-2,7-fluorenyl moiety are made. Structure-property relationships regarding ancillary ligand, bridging moiety, and number of metal centers are drawn.

Development and initial psychometric testing of a body-image domain within an electronic pelvic floor questionnaire (ePAQ-pelvic floor).

INTRODUCTION: Urogynaecological conditions have been shown to negatively impact on body image in a number of previous studies. ePAQ-Pelvic Floor (ePAQ-PF) is a patient-reported outcome measure used in clinical practice to assess urogynaecological conditions and their impact on quality of life. This study aimed to develop and undertake initial psychometric testing of a new domain to assess urogynaecological body image within ePAQ-PF. METHODS: A patient involvement group, analysis of free-text data from ePAQ-PF and a systematic review of existing PROMs assessing urogynaecological body image informed the content of a new body-image domain within ePAQ-PF. This was administered to 208 patients who consented to the use of their anonymised ePAQ-PF responses for research purposes. These data underwent factor analysis, internal consistency reliability and item-total correlation testing. Evidence-based hypotheses were formulated to test construct validity. Criterion validity was assessed against the Body-image Scale (BIS). Patients completed a separate questionnaire (QQ-11) to measure the face validity of ePAQ-PF. RESULTS: Factor analysis revealed a four-item body-image domain with good internal consistency reliability (Cronbach's α = 0.899) and item-total correlation (Spearman's rank r > 0.40). ePAQ-PF body-image domain scores correlated significantly with the BIS scores (r = 0.501). Age, prolapse, sexual dysfunction, pelvic pain and urinary incontinence scores correlated significantly with body-image domain score. QQ-11 value scores demonstrated good acceptability. CONCLUSIONS: Body-image assessment should form part of routine care in urogynaecology. Preliminary results support the validity, reliability and functionality of the body-image domain in ePAQ-PF. Further psychometric testing of this is required, including tests of responsiveness and stability.

Evidence for the urogynaecology multidisciplinary team meeting: evaluation from a secondary care perspective.

INTRODUCTION: Urogynaecology multidisciplinary team (MDT) meetings to discuss management plans prior to invasive treatments for urinary incontinence have been recommended by guidelines in the UK since 2013. Evidence for MDT discussion in urogynaecology is lacking, with only two published studies. The aim of this study was to evaluate the cases discussed at a secondary care urogynaecology MDT meeting, to establish types of clinical problems discussed, assess the outcomes of the MDT meeting and compare this with existing evidence for MDT meetings in urogynaecology. METHODS: A retrospective review of meeting minutes and all case notes for patients discussed at 12 MDT meetings over 13 months was carried out. Data collected included attendance from different staff groups, reasons for referral, outcome of discussions, and changes to management plans. RESULTS: A total of 123 cases were discussed over 12 meetings, 7 members of staff attended each meeting on average. 63% of cases were referred for discussion of a primary problem. The majority of patients were referred for discussion of management of urinary incontinence prior to invasive procedures (57%). The agreed MDT plan corresponded with proposed management in 67% of cases, with changes to management plan in 31% of cases. CONCLUSION: Refinements to management plans in this study highlight the importance of MDT input in urogynaecology care and mirror the findings of two previous studies. Evidence for improved outcomes and the cost-effectiveness of MDTs is lacking and is an area for future research. Expanded national guidance for urogynaecology MDTs is likely to require local and regional restructuring of these in the UK.

Patient-reported outcome measures which assess body image in urogynaecology patients: a systematic review.

AIM: Urogynaecological conditions can have a significant impact on body image. Patient-reported outcome measures (PROMs) are widely used in urogynaecology to assess symptoms and their impact on quality of life. This systematic review aimed to identify currently available PROMs used to assess body image within a urogynaecological population and to identify the most psychometrically robust and appropriate PROM tools to use in this context. METHODS: Ovid Medline, AMED, CINAHL, Cochrane Collaboration, EMBASE and Web of Science databases were searched from January 1966 to November 2018 to identify studies that had administered a PROM to assess body image to patients diagnosed with a urogynaecological condition. The information extracted and critically appraised included study setting, PROM instrument used and the reported psychometric properties of the PROM. RESULTS: Seventeen studies were included from 3207 screened articles. Seven different PROMs used to assess body image in a urogynaecological population were identified. Two of these PROMs (Genital Self-Image Scale-20 and Body Image in Pelvic Organ Prolapse questionnaire) had good psychometric evidence for use, but this was only in the context of women with prolapse. Evidence for validity and reliability was limited for the other five PROMs identified. CONCLUSION: Further development and psychometric testing of PROMs to assess body image in urogynaecology, for both research purposes and clinical practice, are required. Further research is also required to investigate the relationship between body image and urogynaecological symptomatology, and developing valid, reliable and functional PROMs will be integral to this.

A systematic review of non-invasive modalities used to identify women with anal incontinence symptoms after childbirth.

INTRODUCTION AND HYPOTHESIS: Anal incontinence following childbirth is prevalent and has a significant impact upon quality of life (QoL). Currently, there is no standard assessment for women after childbirth to identify these symptoms. This systematic review aimed to identify non-invasive modalities used to identify women with anal incontinence following childbirth and assess response and reporting rates of anal incontinence for these modalities. METHODS: Ovid Medline, Allied and Complementary Medicine Database (AMED), Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Collaboration, EMBASE and Web of Science databases were searched for studies using non-invasive modalities published from January 1966 to May 2018 to identify women with anal incontinence following childbirth. Study data including type of modality, response rates and reported prevalence of anal incontinence were extracted and critically appraised. RESULTS: One hundred and nine studies were included from 1602 screened articles. Three types of non-invasive modalities were identified: validated questionnaires/symptom scales (n = 36 studies using 15 different instruments), non-validated questionnaires (n = 50 studies) and patient interviews (n = 23 studies). Mean response rates were 92% up to 6 weeks after childbirth. Non-personalised assessment modalities (validated and non-validated questionnaires) were associated with reporting of higher rates of anal incontinence compared with patient interview at all periods of follow-up after childbirth, which was statistically significant between 6 weeks and 1 year after childbirth (p < 0.05). CONCLUSIONS: This systematic review confirms that questionnaires can be used effectively after childbirth to identify women with anal incontinence. Given the methodological limitations associated with non-validated questionnaires, assessing all women following childbirth for pelvic-floor symptomatology, including anal incontinence, using validated questionnaires should be considered.

Highly Efficient Red-Emitting Bis-Cyclometalated Iridium Complexes.

Bis-cyclometalated iridium complexes with enhanced phosphorescence quantum yields in the red region of the visible spectrum are described. Here, we demonstrate that incorporating strongly π-donating, nitrogen-containing ß-ketoiminate (acNac), ß-diketiminate (NacNac), and N, N'-diisopropylbenzamidinate (dipba) ancillary ligands can demonstrably perturb the excited-state kinetics, leading to enhanced photoluminescence quantum yields (ΦPL) for red-emitting compounds. A comprehensive study of the quantum yields and lifetimes for these complexes reveals that for the compounds with the highest quantum yields, the radiative rate constant ( kr) is significantly higher than that of related complexes, and contributes substantially to the increase in ΦPL. Experimental and computational evidence is consistent with the notion that an increase in spin-orbit coupling, caused by an enhancement of the metal-to-ligand charge transfer (MLCT) character of the excited state via destabilization of the HOMO, is mainly responsible for the faster radiative rates. One of the compounds was shown to be effective as the emissive dopant in an organic light-emitting diode device.

Development and Psychometric Testing of an Electronic Patient-Reported Outcome Tool for Vulval Disorders (ePAQ-Vulva).

OBJECTIVE: Development of an electronic patient-reported outcome measure (PROM) specifically designed for vulval disorders. Psychometric testing of the components of the questionnaire, which assess vulval symptoms, sexual function, and quality of life (QoL). MATERIALS AND METHOD: Development and programming of the instrument (ePAQ-Vulva) was informed by national guidelines for the assessment of vulval disorders, an expert panel, and a survey of 61 vulval clinic patients. The PROM assesses frequency and impact of vulval symptoms, sexual function, and QoL. It also records conditions and behaviors related to vulval disorders and patient concerns/goals.Scale generation and psychometric testing were undertaken for the vulval symptoms, sexual function, and QoL components of the PROM with 91 participants; descriptive statistics, factor analysis and internal reliability of identified domains, and agreement between free-text and multiple-choice items to assess convergent validity and interrater reliability of picture items were assessed. RESULTS: Descriptive statistics showed high floor effects for seven questionnaire items. Factor analysis identified 5 principal components. These were reviewed and amended to provide a putative domain structure of 6 domains. Internal reliability of these domains was assessed using Cronbach α, producing values of 0.715 to 0.917. Interrater reliability of the picture items produced a κ statistic of 0.405. Spearman rank showed moderate correlation between multiple-choice answers and free-text concerns (r = 0.364-0.462) in 3 of the 6 domains (pain, sex, and dyspareunia). CONCLUSIONS: ePAQ-Vulva offers the first patient-reported outcome tool, specifically designed for vulval disorders. The instrument requires further validation and testing, including evaluation of the stability, responsiveness, and reliability.

Geminally diaurated aryls bridged by semirigid phosphine pillars: syntheses and electronic structure.

Geminally diaurated µ2 -aryl complexes have been prepared where gold(I) centers were bridged by the semirigid diphosphine ligands bis(2-diphenylphosphinophenyl)ether (DPEphos) and 4,6-bis(diphenylphosphanyl)dibenzo[b,d]furan (DBFphos). Diaurated complexes were synthesized in ligand redistribution reactions of the corresponding di-gold dichlorides with di-gold diaryls (six of them new) and silver(I) salts. Diaurated complexes were isolated as salts of the minimally coordinating anions SbF6 (-) and ReO4 (-). Efforts to prepare salts of the tetraarylborate [B(3,5-(CF3)2 C6 H3)4](-) led to transmetalation from boron, with crystallization of the fluorinated aryl complex. The new complexes were characterized by multinuclear NMR, absorption and emission spectroscopies, 77 K emission lifetimes, and by combustion analysis; three are crystallographically characterized. Structures of geminally diaurated aryl ligands are compared to those of mono-aurated analogues. Both crystal structures and density-functional theory calculations indicate slight but observable disruptions of aryl ligand aromaticity by geminal di-gold binding. An intermolecular aurophilic interaction in one structurally authenticated complex was examined computationally.

Patient-initiated follow-up in gynaecology: Patient and clinician views.

OBJECTIVES: Follow-up appointments in the UK National Health Service account for up to two thirds of outpatient activity, but there is a significant resource impact in providing time fixed follow-up appointments. Increasingly patient initiated follow-up is being used, to make follow-up appointments work better for patients both in terms of timing and necessity, and to reduce unnecessary outpatient activity. The objective of this study was to use a modified questionnaire to evaluate patient and clinician views regarding Patient-Initiated Follow-Up (PIFU) in gynaecology services and identify subgroups suited to this pathway of care. STUDY DESIGN: Participants including both patients and clinicians were recruited from a gynaecology outpatient department. Patients who have poorer access healthcare (with disabilities and black and ethnic minority background) were purposively targeted so their experiences could be included. Value and burden scores were evaluated using patient and clinician surveys based on a modified QQ-10 questionnaire which assessed perceived value and burden of patient initiated follow-up in gynaecology. Free text comments regarding PIFU were also collected. RESULTS: 305 patients and 30 clinicians were surveyed. Overall response to patient initiated follow-up was positive. Patients and clinicians attributed high value (77.4 % and 81.4 %) and low burden scores (37.5 % and 44.7 %) to PIFU. Patient autonomy was cited as a reason for this by 84.6 % of patients and 93.3 % of clinicians. Patients attending benign gynaecological sub-specialties including endometriosis (84.2), general gynaecology (82.5) and vulval clinics (81.4) attributed the highest value scores. Gynaecology oncology patients attributed the lowest value (64.0) and highest burden score (51.3) of all subgroups. Younger adults (<60) were more likely to express a preference for PIFU (52.9 %) than older adults (≥60) (28.6 %). CONCLUSIONS: In this study, both patients and clinicians are in favour of selected use of PIFU in gynaecology services. Both questionnaires found younger patients with benign gynaecological conditions were perceived as best suited PIFU. We recommend offering PIFU to select patients who are confident in self-monitoring, factoring patient choice so patients are not disadvantaged by this system. Further evaluation of PIFU in practice is needed before widespread implementation.

Cyclometalated iridium(III) complexes with deoxyribose substituents.

Fundamental study of enzymatic nucleoside transport suffers for lack of optical probes that can be tracked noninvasively. Nucleoside transporters are integral membrane glycoproteins that mediate the salvage of nucleosides and their passage across cell membranes. The substrate recognition site is the deoxyribose sugar, often with little distinction among nucleobases. Reported here are nucleoside analogues in which emissive, cyclometalated iridium(III) complexes are "clicked" to C-1 of deoxyribose in place of canonical nucleobases. The resulting complexes show visible luminescence at room temperature and 77 K with microsecond-length triplet lifetimes. A representative complex is crystallographically characterized. Transport and luminescence are demonstrated in cultured human carcinoma (KB3-1) cells.

Azadipyrromethene complexes of d8 metal centers: rhodium(I), iridium(I), palladium(II), and platinum(II).

Azadipyrromethenes are blue pigments that chelate main-group and d-block Lewis acids. Reported here are azadipyrromethene complexes of d(8) metal centers. The new compounds are prepared in salt metathesis reactions with chlorinated organometallic precursors. Sixteen new complexes are reported. The principal absorption features are an intense peak near 600 nm and transitions in the ultraviolet; all are characteristic of the azadipyrromethene chromophore. All compounds are dark solids that yield blue or blue-violet solutions. Ten complexes are crystallographically characterized. The structures uniformly show backbone strain, with a meso-nitrogen atom that dilates from pure sp(2)-hybridization. Structural comparisons are made to related dipyrromethene and tetra-azaporphyrin complexes. The electron-donating capacity of azadipyrromethene ligands is evaluated from C≡O stretching frequencies of three rhodium(I) carbonyl complexes and from density-functional theory calculations. Frontier orbitals are confined to the azadipyrromethene ligand. HOMO-LUMO energy gaps are almost unperturbed from those of the free, anionic azadipyrromethene.