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BackgroundRates of infection after inflatable penile prosthesis range from 1% to 3%; however, a new surgical irrigation solution is Food and Drug Administration cleared as antimicrobial wound lavage and appears to be safe for patients and noncaustic during hydrophilic inflatable penile prosthesis (hIPP) dipping and irrigation.AimTo evaluate if 0.05% chlorhexidine (CHG) lavage is caustic to the hIPP coating and if dip adherence is dependent on time.MethodsPreconnected hIPP devices were tested at a Coloplast research and development laboratory. The devices were soaked in the 0.05% CHG lavage solution or normal saline for 1, 15, 30, and 60 minutes. Subsequently, all parts were dried for 15 minutes in a 35 °C oven. A Congo red dye test was performed following a Coloplast-validated and Food and Drug Administration–cleared test method to ensure product reliability. Implants were then visually inspected for deleterious effects as well as dip coverage. In addition, we evaluated 0.05% CHG lavage solution vs previously published hIPP dipping solutions.Outcomes0.05% CHG lavage does not appear to damage the hIPP coating, and adherence of this solution is not dependent on dip time.ResultsAll components of the preconnected hydrophilic IPPs were tested for coating adherence and defects. All tested IPPs achieved a “satisfactory” coating, meaning a uniform coat without flaking or clumping. Furthermore, there were no noticeable caustic effects or differences in coating adherence between the normal saline–soaked control and 0.05% CHG–coated arms with increasing dip time. A review of the literature for 0.05% CHG lavage solutions vs previously published hIPP dipping solutions revealed that it may have some advantages over previously reported antibiotic solutions.Clinical ImplicationsThis study serves as a foundation to introduce 0.05% CHG lavage to the urologic literature as a potentially new “magic bullet” irrigation.Strengths and LimitationsMajor strengths of the study are that it is the first study of its kind to address the question of what dip duration should be used and whether it is scientifically reproducible. A limitation is the in vitro model, thus needing validation in a clinical setting.Conclusion0.05% CHG does not appear to negatively affect the hIPP coating or differ in adherence with increasing dip time; however, long-term device performance has not been verified.

Purpose: Many providers elect to use a transcorporeal approach for artificial urinary sphincter placement in an attempt to minimize risks, given the increased risk of complications in revision cases. We present outcomes in a multicenter retrospective analysis of artificial urinary sphincter cuff reimplantation in patients with prior cuff erosion with special consideration given to the transcorporeal approach.Materials and Methods: We compiled a multi-institutional database of patients who underwent artificial urinary sphincter reimplantation after prior urethral erosion. Of the 34 identified patients 24 underwent transcorporeal cuff replacement. Patients with transcorporeal cuff replacement were further analyzed with specific stratification for radiation therapy.Results: The rate of subsequent complications after eroded cuff reimplantation was 32.4% (11 of 34 patients). The most frequent complication was recurrent erosion, which developed in 9 of the 34 patients (26.4%). Repeat artificial urinary sphincte...

Substantial controversy and conflicting data exist regarding the survival of the artificial urinary sphincter in patients with prior radiation therapy. We present data from a multi-institutional analysis examining the effect of prior radiation for prostate cancer on device survival.A database was compiled of patients with artificial urinary sphincter cuff erosion, which included demographic and comorbid patient characteristics, functional analyses and interventions. We identified 80 patients with iatrogenic or idiopathic artificial urinary sphincter erosion. Idiopathic erosion cases were further analyzed to determine factors influencing device survival with specific stratification for radiation therapy.A total of 56 patients were identified with idiopathic artificial urinary sphincter erosion. Of those men 33 (58.9%) had not undergone radiation treatment while 23 (41.1%) had a history of brachytherapy or external beam radiotherapy. In patients without radiation erosion-free median device survival was 3.15 years (95% CI 1.95-5.80), in contrast to the median device survival of only 1.00 year (95% CI 0.36-3.00) in irradiated patients. The erosion-free survival experience of patients with vs without radiation differed significantly (Wilcoxon-Breslow test for equality of survivor functions p = 0.03).Radiation therapy in patients with known idiopathic cuff erosion in this contemporary analysis correlated with significantly increased time to erosion. Mean time to idiopathic cuff erosion was accelerated by approximately 2 years in irradiated cases. To our knowledge these data represent the first demonstration of substantial outcome differences associated with radiation in patients with an artificial urinary sphincter who present specifically with cuff erosion.

Objective To evaluate the influence of both repair type and degree of cuff erosion on postoperative urethral stricture rate. Sparse literature exists regarding patient outcomes after artificial urinary sphincter (AUS) cuff erosion. Surgeons from 6 high-volume male continence centers compiled a comprehensive database of post-erosion patients to examine outcomes. Materials and Methods This retrospective multi-institution study included 80 patients treated for AUS cuff erosions. Seventy-eight patients had specific information regarding post-cuff erosion urethral strictures. Erosion patients were categorized into 1 of 3 repair types at the time of explant surgery: catheter only, single-layer capsule-to-capsule repair (urethrorrhaphy), and formal urethroplasty. Operative notes and available medical records were extensively reviewed to collect study data. Results Twenty-five of 78 patients manifested a urethral stricture after AUS cuff erosion (32%). More strictures occurred among patients who underwent urethrorrhaphy (40% vs 29% for catheter only and 14% for urethroplasty). Stricture rates did not vary significantly by repair type ( P = .2). Strictures occurred significantly more frequently in patients with complete cuff erosions (58%) as compared to partial erosions (25%, P = .037). A trend was detected regarding increased percentage of erosion correlating with increased stricture rate, but this did not reach statistical significance ( P = .057). Partially eroded patients were more likely to undergo urethrorrhaphy repair (60%, P = .002). Conclusion Urethral stricture was more likely to occur after complete cuff erosion as opposed to partial erosion in this multicenter retrospective population. Repair type, whether catheter only, urethrorrhaphy, or formal urethroplasty, did not appear to influence postoperative stricture rate.

INTRODUCTION AND OBJECTIVES:Constraints on surgical resident training and inequalities in the availability of expert surgical educators may limit the acquisition of prosthetic surgical skills. As a...

Introduction Constraints on surgical resident training (work-hour mandates, shorter training programs, etc.) and availability of expert surgical educators may limit the acquisition of prosthetic surgical skills. As a result, training courses are being conducted to augment the prosthetic surgery learning experience. Aim To evaluate the impact of a hands-on cadaver-based teaching program on resident procedural knowledge and procedural confidence with placement of a penile prosthesis. Main Outcome Measure Changes in procedural knowledge and self-confidence following a focused training program on penile prosthetics. Methods As part of the 2017 Society of Urologic Prosthetic Surgeons and the Sexual Medicine Society of North America Annual Meeting, 31 urology residents participated in a simulation lab in prosthetic urology. The lab included didactic lectures and a hands-on cadaveric laboratory. Participants completed surveys before and after the course. Wilcoxon Signed Rank tests for matched pairs were used to compare respondents’ pre- and postcourse knowledge (% questions answered correctly) and confidence ratings. Prior implant experience was assessed. Results 31 residents participated in this study. The majority of the participants were 4th- (41.9%) and 5th-year residents (38.7%). Participants showed a significant improvement in procedural knowledge test scores (68.8±13.4 vs 74.2 ± 13.0, P < .05) and self-reported increased median surgical confidence levels (4 vs 3, P value < .001) after completion of the cadaveric course. Subgroup analysis demonstrated that residents with prosthetic surgery experience of Conclusion Simulation training in prosthetic surgery seems to improve surgical confidence and knowledge. Further research is needed to better understand the benefits and limitations of simulation training.

To date, the published data on patients treated with penile implantation generally consist of small series of single surgeon, retrospective experiences rather than prospective or large, multicenter evaluations. This study establishes a baseline of data collection from the PROPPER (Prospective Registry of Outcomes with Penile Prosthesis for Erectile Restoration). The PROPPER is the first large, prospective, multicenter, multinational, monitored, and internal review board approved study of real-world outcomes for patients with penile implants.Data from the PROPPER study were examined to determine patient baseline characteristics and primary and secondary etiologies before treatment of erectile dysfunction. Data include type and size of implant received, surgical steps/techniques used during implantation, and duration of hospital stay.Through April 2, 2015 a total of 1,019 patients were enrolled in the study at 11 sites, with radical prostatectomy being the predominant etiology in 285 (28%). Of those 285 patients treated with radical prostatectomy 280 (98.2%) received an AMS 700™. Of these patients 65.0% (182 of 280) had placement of the reservoir in the traditional retropubic space vs 31.8% (89 of 280) in a submuscular location. Of those patients not treated with radical prostatectomy receiving an AMS 700, fewer underwent reservoir placement in the submuscular location (17.7%, 124 of 702, vs 80.9%, 568 of 702; p0.001). Of those patients receiving an AMS 700, those treated with radical prostatectomy and those with diabetes had more outpatient admissions (less than 24 hours, 56.8% and 52.1%, respectively) compared to those with cardiovascular disease and Peyronie's disease (42.0% and 35.6%, respectively, p0.001).This first-of-its-kind, large, prospective, multicenter study reveals most penile implant cases in North America receive an inflatable penile prosthesis and that radical prostatectomy is the most common primary etiology of penile implant surgery. Moreover, patients treated with radical prostatectomy were more likely to have the reservoir placed in a submuscular location, have a longer operating room time and be admitted to the hospital overnight compared with other patient groups.

Alternative reservoir site placement has become an accepted technique for patients who require an inflatable penile prosthesis. To our knowledge there has been no prospective evaluation of this technique, which is currently off label. We performed a prospective, multicenter, multinational, internal review board approved study to evaluate the effectiveness and safety of alternative reservoir site placement.PROPPER initiated in June 2011, is a database containing patient outcomes of inflatable penile prosthesis implantation. Patients with AMS® penile prostheses continue to be enrolled at 13 North American sites. We examined PROPPER study data to determine surgical implantation use patterns for the AMS 700™ series. We evaluated reservoir implantation site and complications by implantation site.A total of 759 patients had been implanted with an AMS 700 series implant by the time of evaluation. Mean patient followup was 17.8 months (range 0 to 36). There was no reported case of revision surgery for a palpable reservoir and no report of vascular or hollow viscous injury associated with alternative reservoir site placement. Two cases of reservoir herniation in the alternative reservoir site placement group and 2 in the space of Retzius group were treated with reservoir reimplantation. Patients with 1-year assessment available were satisfied or very satisfied with the device and reported a frequency of use of more than once per month.Alternative reservoir placement in the submuscular location is an option in patients who undergo inflatable penile prosthesis surgery. Implant surgeons should consider alternative reservoir site placement a safe, effective alternative to reservoir placement in the space of Retzius.

Objective To issue a consensus document on the prevention, management, and research of infection associated with penile prostheses, as neither professional associations nor governmental entities have issued guidelines that are specific to this infection. Methods Sixteen North American experts on infection of penile prostheses were identified and assembled to select and discuss certain issues related to infection of penile prostheses. After performing an extensive search of clinically important issues in published reports, the 16 experts met twice in person to finalize the selection, discuss the issues that were deemed most important, and issue pertinent recommendations. Results Although many subjects relevant to infection of penile prostheses were initially identified, the experts selected 10 issues as currently being the most important issues and for which there exists some support in the published data. The examined issues involved prevention, management, or research of infections associated with penile prostheses. Conclusion In the absence of pertinent guidelines, the consensus document issued by experts in the field of prosthetic urology is anticipated to improve the quality of patient care, streamline the prevention and management of infected penile prostheses, and stimulate collaborative research. Although this consensus document could serve as best practice recommendations, the lack of adherence to these recommendations would not indicate improper care.

Summary Aim: Determine the long-term efficacy, safety and tolerability of avanafil, a highly specific, rapidly absorbed phosphodiesterase type 5 inhibitor in male patients with mild to severe erectile dysfunction (ED), with or without diabetes. Methods: This was a 52-week, open-label extension of two 12-week, randomised, placebo-controlled, phase 3 trials. Patients were assigned to avanafil 100 mg, but could request 200 mg (for increased efficacy; ‘100/200-mg’ group) or 50 mg (for improved tolerability). Primary end points included percentage of sexual attempts ending in successful vaginal penetration [Sexual Encounter Profile 2 (SEP2)] and intercourse (SEP3) and erectile function domain score per the International Index of Erectile Function (IIEF-EF). Results: Some 712 patients enrolled; 686 were included in the intent to treat population and contributed to the data. All primary end points showed sustained improvement. SEP2 and SEP3 success rates improved from 44% to 83% and from 13% to 68% (100-mg group) and from 43% to 79% and from 11% to 66% (100/200-mg group), respectively. Mean IIEF-EF domain scores improved from 13.6 to 22.2 (100-mg group) and from 11.9 to 22.7 (100/200-mg group). Avanafil was effective in some patients ≤ 15 min and > 6 h postdose. Sixty-five per cent (112/172) of ‘nonresponders’ to avanafil 100 mg responded to the 200-mg dose. The most common (≥ 2%) treatment-emergent adverse events were headache, flushing, nasopharyngitis and nasal congestion

INTRODUCTION AND OBJECTIVES: In 2013, the FDA approved collagenase clostridium histolyticum (CCH) (Xiaflex ) for use in men with Peyronie’s disease who demonstrate a palpable penile plaque and penile curvature of >30 . Currently, there is limited data on the clinical outcomes since approval of this medication. Given this gap in knowledge, we conducted a review of all patient visits for CCH administration with the aim of reporting on real world clinical outcomes and adverse effects. METHODS: After IRB approval, a retrospective study from 2 large-volume centers was conducted to assess patient outcomes and complications associated with CCH injection. Eligible study candidates included those with documented penile curvature of between 30 and 90 and a palpable penile plaque. The risk evaluation and mitigation strategy (REMS) protocol was followed as described in the CCH prescribing information. Adverse events and treatment response were documented after each patient encounter. RESULTS: Fifty-five men received 338 plaque injections with CCH from April 2014 thru August 2015. Of the 55 men identified, 36 (65.5%) experienced penile, suprapubic or scrotal ecchymosis. Additional adverse effects included post injection penile erythema (30.9%), penile pain (23.6%), penile edema (18.4%), hematoma formation (9.1%), penile blister (7.3%), penile hemorrhage (3.6%) and corporal rupture (3.6%). One corporal rupture occurred with aggressive vacuum erection device use within 2 weeks of CCH injection. The injury was diagnosed with pelvic MRI and required no operative intervention. The second occurred with penile fracture during sexual activity 4 weeks after the first cycle and operative intervention was required. Plaque softening was observed in 50 (89.5%) men while 41 (73.7%) reported improvement in curvature. CONCLUSIONS: CCH is a safe and effective treatment option for men with Peyronie’s disease. Minor adverse effects may be anticipated but are typically short lived. This study emphasizes the need for strict compliance with the REMS program, as corporal rupture is being reported in real-world clinical experience. Physicians administering Xiaflex need to be able to manage corporal rupture. Additionally, the majority of men report improvement in penile curvature and plaque composition.

Introduction A single‐armed, prospective, multicenter international study evaluated the redesigned Coloplast Titan One Touch Release (OTR) pump inflatable penile prosthesis. The OTR pump has a unique release valve that permits deflation of the implant with one squeeze of opposing touch pads. Aims To assess the impact of a new penile prosthesis design, the Titan OTR, on patient ease of operation. Furthermore, to assess patient satisfaction, surgeon acceptance, and the ease with which patients were trained in device operation in the clinic setting. Methods A total of 113 eligible patients from eight centers were recruited from men presenting with erectile dysfunction without prior prosthetic implantation. The subjects had a mean age of 61 years, and had a number of comorbidities, including diabetes (31.9%), hypertension (34.5%), and Peyronie's disease (23.9%). All underwent implantation of the study device. Main Outcome Measures Questionnaires were used to capture patient satisfaction as well as physician feedback on ease of implantation and patient education. A paired analysis was completed for patient satisfaction at 6 (N = 96) and 12 (N = 90) months. Results Overall satisfaction with the device was 90.6% and 90.0% at 6 and 12 months, respectively. The primary end point, ease of deflation, was seen in 70.8% and 73.3% at these two time points, with the 12‐month value statistically better than historical controls. Physicians overwhelmingly reported straightforward/simple intraoperative product preparation (97.3%) and equivalent or easier training compared with their previous pump of choice (96.4%). Adverse events for all subjects (N = 113) included removal of the device in four cases (3.5%) for infection and one case for chronic pain (0.8%). Conclusions The Titan OTR represents an advance in penile prosthetic technology that is well accepted by patients and physicians. The study design allowed for realistic evaluation of the new technology aimed at enhancing clinical outcomes. Ohl DA, Brock G, Ralph D, Bogache W, Jones L, Munarriz R, Levine L, and Ritenour C. Prospective evaluation of patient satisfaction, and surgeon and patient trainer assessment of the Coloplast Titan One Touch Release three‐piece inflatable penile prosthesis. J Sex Med 2012;9:2467–2474.

Introduction Phosphodiesterase type 5 (PDE5) inhibitors have become standard treatment for erectile dysfunction (ED). Aim To prospectively evaluate the safety and efficacy of avanafil, a novel PDE5 inhibitor, in men with mild to severe ED. Methods In this multicenter, double‐blind, Phase 3 trial, 646 subjects were randomized to receive avanafil (50 mg, 100 mg, 200 mg) or placebo throughout a 12‐week treatment period. Subjects were instructed to take study drug 30 minutes prior to initiation of sexual activity. At least a 12‐hour separation time between doses was required; no restrictions were placed on food or alcohol intake. Main Outcome Measures Improvement in erectile function (EF) was measured by Sexual Encounter Profile questions 2 and 3 (SEP2 and SEP3) and by the EF domain of the International Index of Erectile Function (IIEF) questionnaire. Results Mean change in percentage of successful sexual attempts (SEP2 and SEP3) and IIEF‐EF domain score significantly favored all doses of avanafil over placebo ( P ≤ 0.001). Secondary analyses demonstrated achievement of successful intercourse by subjects within 15 minutes of dosing. Of the 300 sexual attempts made during this interval, 64% to 71% were successful in avanafil‐treated subjects compared with 27% in placebo‐treated subjects. Successful intercourse was also demonstrated >6 hours post dosing, with 59% to 83% of the 80 sexual attempts successful in avanafil‐treated subjects compared with 25% of placebo‐treated subjects. The most commonly reported adverse events in subjects taking avanafil included headache, flushing, and nasal congestion; there were no drug‐related serious adverse events. Conclusion Following 12 weeks of avanafil treatment without food or alcohol restrictions, significant improvements in sexual function were observed with all 3 doses of avanafil compared with placebo. Successful intercourse was observed as early as 15 minutes and >6 hours after dosing in some subjects. Avanafil was generally well tolerated for the treatment of ED. Goldstein I, McCullough AR, Jones LA, Hellstrom WJ, Bowden CH, DiDonato K, Trask B, and Day WW. A randomized, double‐blind, placebo‐controlled evaluation of the safety and efficacy of avanafil in subjects with erectile dysfunction. J Sex Med 12;9:1122–1133.

The Sexual Experience Questionnaire (SEX-Q) enables quick and easy assessment of functional, emotional, and satisfaction-related aspects of the sexual experience in men with erectile dysfunction (ED).To assess correlations between improvement on the SEX-Q and outcomes on other validated questionnaires. METHODS. Men with ED (scoreor =25 on the Erectile Function domain of the International Index of Erectile Function [IIEF]) who had used less than or equal to six doses of any phosphodiesterase 5 inhibitor (none within 6 months) were randomized to 10 weeks of double-blind, placebo-controlled (DBPC) flexible-dose sildenafil citrate (50 or 100 mg, as needed), followed by 6 weeks of open-label (OL) sildenafil.SEX-Q, IIEF, Quality of Erection Questionnaire (QEQ), Self-Esteem and Relationship (SEAR) Questionnaire, Erection Hardness Score (EHS), successful intercourse attempts (SIAs), Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS), and global efficacy questions (GEQs).Compared with the placebo group (N = 105), the sildenafil group (N = 104) at DBPC end of treatment (EOT) had significantly more improvement (P0.05) on all SEX-Q, IIEF (except the Sexual Desire domain), QEQ, and SEAR outcomes, more frequent SIAs and EHS 3 (hard enough for penetration but not completely hard) or EHS 4 (completely hard) erections (odds ratio [OR], 2.52 and 3.46, respectively), EHS 4 erections four times as often (OR, 6.41), more men satisfied with treatment (EDITS; OR, 2.6), approximately twice as many men with improved erections (GEQ1; OR, 5.8) and ability to have sexual intercourse (GEQ2; OR, 5.4), and GEQ3 scores that indicated better sex (P0.0001). SEX-Q score improvements correlated positively with all other outcomes. At OL EOT, most outcomes were60% (and approximately half wereor =80%) of the maximum positive result.SEX-Q change scores correlate with several other functional, emotional, and satisfaction-related outcomes in men treated with sildenafil for ED, allowing a simple and focused evaluation of the sexual experience.

Introduction The advent of the penile prosthesis revolutionized the treatment of erectile dysfunction (ED), resulting in near-complete treatment efficacy and high patient satisfaction rates. While several types of penile prosthesis are available, the inflatable penile prosthesis (IPP) is the most commonly used device in the United States. Aims To describe the key modifications to IPPs from the two major manufacturers—American Medical Systems (AMS) and Coloplast—since the invention of the IPP, and to relate these changes to improvements in prosthesis function and patient outcomes based on available literature. Methods Review and evaluation of the literature between 1973 and present describing modifications in IPP design and the influence of these modifications on IPP durability and patient-related factors. Main Outcome Measures Data describing the impact of iterative improvements in three-piece IPP design on device function, durability, and patient outcomes. Results There were progressive improvements in IPP technology from both major manufacturers not only on the durability of the prosthesis but also on patient outcomes, with fewer device failures and lower infection rates. Notable improvements include incorporation of kink-resistant tubing, changes in the weave or addition of shear- and infection-resistant coatings to cylinder layers, pump and tubing connection modifications, the addition of rear tip extenders, and the incorporation of lockout valves to prevent autoinflation. Conclusions Numerous incremental modifications to the IPP from both major manufacturers since its invention have increased its durability and improved patient outcomes.

Molecular resolution scanning tunneling microscopy (STM) imaging and high sensitivity infrared reflection spectroscopy (IRS) measurements have been combined to characterize the structures of mixed self-assembled monolayers (SAMs) of fully conjugated, linear thiolate-terminated molecules and short chain (8−12) n-alkanethiolates on Au{111}. Immersion of preformed, ordered alkanethiolate SAMs into dilute solutions of the conjugated molecules results in two-dimensional matrix isolation of conjugated adsorbates in the host SAM. The post-immersion host SAM matrix shows retained alkanethiolate ordering with the guest molecules inserted both singly into boundaries between SAM structural domains and in bundles at substrate step edges. Inserted molecules of lengths in the ∼15 A range adopt surface orientations similar to those of alkanethiolate molecules at all compositions, including the pure conjugated SAMs. In contrast, the configuration of an inserted, long conjugated molecule (∼40 A), varies monotonically with...

This paper describes four significant breakthroughs in the syntheses and testing of molecular scale electronic devices. The 16-mer of oligo(2-dodecylphenylene ethynylene) was prepared on Merrifields resin using the iterative divergent/convergent approach which significantly streamlines the preparation of this molecular scale wire. The formation of self-assembled monolayers and multilayers on gold surfaces of rigid rod conjugated oligomers that have thiol, -dithiol, thioacetyl, or -dithioacetyl end groups have been studied. The direct observation of charge transport through molecules of benzene-1, 4-dithiol, which have been self-assembled onto two facing gold electrodes, has been achieved. Finally, we report initial studies into what effect varying the molecular alligator clip has on the molecule scale wire's conductivity.

We present the investigation of the electrical transport of metal/(organic molecule or monolayer)/metal junctions. Utilizing a novel mechanically controllable break junction to form a statically stable system, we have self-assembled molecules of benzene- 1,4-dithiol onto two facing gold electrodes allowing for direct observation of charge transport through the molecules. Current-voltage I(V) measurements provides a quantitative measure of the conductance of a junction containing a single molecule. We have also created a technique to form well-defined, stable, and reproducible metallic contacts to a self-assembled monolayer of 4-thioacetylbiphenyl with nanoscale area. Electronic transport measurements show a prominent rectifying behavior arising from the asymmetry of the molecular heterostructure. Variable-temperature measurements reveal the dominant transport mechanisms, such as thermionic emission for the Ti-organic system. These techniques demonstrate the capability of electrically characterizing and engineering conductive molecular systems for future potential device applications.

This paper describes four significant breakthroughs in the syntheses and testing of molecular scale electronic devices. The 16-mer of oligo(2-dodecylphenylene ethynylene) was prepared on Merrifield's resin using the iterative divergent/convergent approach which significantly streamlines the preparation of this molecular scale wire. The formation of self-assembled monolayers (SAMs) and multilayers on gold surfaces of rigid rod conjugated oligomers that have thiol, α,ω-dithiol, thioacetyl, or α,ω-dithioacetyl end groups have been studied. The direct observation of charge transport through molecules of benzene-1,4-dithiol, which have been self-assembled onto two facing gold electrodes, has been achieved. Finally, we are reporting initial studies into what effect varying the molecular alligator clip has on the molecular scale wire's conductivity.

The syntheses of soluble oligo(2-alkyl-1,4-phenylene ethynylene)s via an iterative divergent/convergent approach starting from 1-(diethyltriazyl)-3-alkyl-4-[(trimethylsilyl)ethynyl]benzenes are described. When the solublizing alkyl group is an ethyl substituent, the monomer, dimer, tetramer, and octamer can be synthesized. The octamer, however, is only minimally soluble. When the alkyl substituent is 3-ethylheptyl or dodecyl, the compounds are easily dissolved even at the 16-mer stage. The 16-mer is 128 A long in its near-linear extended conformation. At each stage in the iteration, the length of the framework doubles. Only three sets of reaction conditions are needed for the entire iterative synthetic sequence: an iodination, a protodesilylation, and a Pd/Cu-catalyzed cross coupling. Synthesis of the dodecyl-containing 16-mer was also achieved on Merrifield's resin using the iterative divergent/convergent approach. The oligomers were characterized spectroscopically and by mass spectrometry. The optical ...