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The aim of this study was to identify a mortality benefit with the use of whole blood (WB) as part of the resuscitation of bleeding trauma patients.Blood component therapy (BCT) is the current standard for resuscitating trauma patients, with WB emerging as the blood product of choice. We hypothesized that the use of WB versus BCT alone would result in decreased mortality.We performed a 14-center, prospective observational study of trauma patients who received WB versus BCT during their resuscitation. We applied a generalized linear mixed-effects model with a random effect and controlled for age, sex, mechanism of injury (MOI), and injury severity score. All patients who received blood as part of their initial resuscitation were included. Primary outcome was mortality and secondary outcomes included acute kidney injury, deep vein thrombosis/pulmonary embolism, pulmonary complications, and bleeding complications.A total of 1623 [WB: 1180 (74%), BCT: 443(27%)] patients who sustained penetrating (53%) or blunt (47%) injury were included. Patients who received WB had a higher shock index (0.98 vs 0.83), more comorbidities, and more blunt MOI (all P0.05). After controlling for center, age, sex, MOI, and injury severity score, we found no differences in the rates of acute kidney injury, deep vein thrombosis/pulmonary embolism or pulmonary complications. WB patients were 9% less likely to experience bleeding complications and were 48% less likely to die than BCT patients ( P0.0001).Compared with BCT, the use of WB was associated with a 48% reduction in mortality in trauma patients. Our study supports the use of WB use in the resuscitation of trauma patients.

Treating older trauma patients requires a focus on the confluence of age-related physiological changes and the impact of the injury itself. Therefore, the primary way to improve the care of geriatric trauma patients is through the development of universal, systematic multidisciplinary research. To achieve this, the Coalition for National Trauma Research has developed the National Trauma Research Action Plan that has generated a comprehensive research agenda spanning the continuum of geriatric trauma care from prehospital to rehabilitation.Experts in geriatric trauma care and research were recruited to identify current gaps in clinical geriatric research, generate research questions, and establish the priority of these questions using a consensus-driven Delphi survey approach. Participants were identified using established Delphi recruitment guidelines ensuring heterogeneity and generalizability. On subsequent surveys, participants were asked to rank the priority of each research question on a nine-point Likert scale, categorized to represent low-, medium-, and high-priority items. The consensus was defined as more than 60% of panelists agreeing on the priority category.A total of 24 subject matter experts generated questions in 109 key topic areas. After editing for duplication, 514 questions were included in the priority ranking. By round 3, 362 questions (70%) reached 60% consensus. Of these, 161 (44%) were high, 198 (55%) medium, and 3 (1%) low priority.Among the questions prioritized as high priority, questions related to three types of injuries (i.e., rib fracture, traumatic brain injury, and lower extremity injury) occurred with the greatest frequency. Among the 25 highest priority questions, the key topics with the highest frequency were pain management, frailty, and anticoagulation-related interventions. The most common types of research proposed were interventional clinical trials and comparative effectiveness studies, outcome research, and health care systems research.

In 2016, the National Academies of Science, Engineering and Medicine called for the development of a National Trauma Research Action Plan. The Department of Defense funded the Coalition for National Trauma Research to generate a comprehensive research agenda spanning the continuum of trauma and burn care. Given the public health burden of injuries to the central nervous system, neurotrauma was one of 11 panels formed to address this recommendation with a gap analysis and generation of high-priority research questions.We recruited interdisciplinary experts to identify gaps in the neurotrauma literature, generate research questions, and prioritize those questions using a consensus-driven Delphi survey approach. We conducted four Delphi rounds in which participants generated key research questions and then prioritized the importance of the questions on a 9-point Likert scale. Consensus was defined as 60% or greater of panelists agreeing on the priority category. We then coded research questions using an National Trauma Research Action Plan taxonomy of 118 research concepts, which were consistent across all 11 panels.Twenty-eight neurotrauma experts generated 675 research questions. Of these, 364 (53.9%) reached consensus, and 56 were determined to be high priority (15.4%), 303 were deemed to be medium priority (83.2%), and 5 were low priority (1.4%). The research topics were stratified into three groups-severe traumatic brain injury (TBI), mild TBI (mTBI), and spinal cord injury. The number of high-priority questions for each subtopic was 46 for severe TBI (19.7%), 3 for mTBI (4.3%) and 7 for SCI (11.7%).This Delphi gap analysis of neurotrauma research identified 56 high-priority research questions. There are clear areas of focus for severe TBI, mTBI, and spinal cord injury that will help guide investigators in future neurotrauma research. Funding agencies should consider these gaps when they prioritize future research.Diagnostic Test or Criteria, Level IV.

The 2016 National Academies of Science, Engineering and Medicine report included a proposal to establish a National Trauma Research Action Plan. In response, the Department of Defense funded the Coalition for National Trauma Research to generate a comprehensive research agenda spanning the continuum of trauma and burn care from prehospital care to rehabilitation as part of an overall strategy to achieve zero preventable deaths and disability after injury. The Postadmission Critical Care Research panel was 1 of 11 panels constituted to develop this research agenda.We recruited interdisciplinary experts in surgical critical care and recruited them to identify current gaps in clinical critical care research, generate research questions, and establish the priority of these questions using a consensus-driven Delphi survey approach. The first of four survey rounds asked participants to generate key research questions. On subsequent rounds, we asked survey participants to rank the priority of each research question on a 9-point Likert scale, categorized to represent low-, medium-, and high-priority items. Consensus was defined as ≥60% of panelists agreeing on the priority category.Twenty-five subject matter experts generated 595 questions. By Round 3, 249 questions reached ≥60% consensus. Of these, 22 questions were high, 185 were medium, and 42 were low priority. The clinical states of hypovolemic shock and delirium were most represented in the high-priority questions. Traumatic brain injury was the only specific injury pattern with a high-priority question.The National Trauma Research Action Plan critical care research panel identified 22 high-priority research questions, which, if answered, would reduce preventable death and disability after injury.Diagnostic Tests or Criteria; Level IV.

Background While massive transfusion protocols (MTP) are associated with decreased mortality in adult trauma patients, there is limited research on the impact of MTP on pediatric trauma patients. The purpose of this study was to compare pediatric trauma patients requiring massive transfusion to all other pediatric trauma patients to identify triggers for MTP activation in injured children. Methods Using our level I trauma center's registry, we retrospectively identified all pediatric trauma patients from January 2015 to January 2018. Massive transfusion (MT) was defined as infusion of 40 mL/kg of blood products in the first 24 hours of admission. Patients missing prehospital vital sign data were excluded from the study. We retrospectively collected data including: demographics, blood utilization, variable outcome data, prehospital vital signs, prehospital transport times, and injury severity scores (ISS). Statistical significance was determined using Mann-Whitney U test and chi-square test. P values less than 0.05 were considered significant. Results Thirty-nine of the 2,035 pediatric patients (1.9%) met criteria for MT. All-cause mortality in MT patients was 49% (19/39) versus 0.01% (20/1996) in Non-MT patients. The two groups significantly differed in ISS, prehospital vital signs, and outcome data.Both systolic blood pressure (SBP) 1.4 were found to be highly specific for massive transfusion with specificities of 86% and 92%, respectively. The combination of SBP 1.4 had a specificity of 94%. The positive and negative predictive values of SBP 1.4 in predicting massive transfusion were 18% and 98%, respectively. Based on positive likelihood ratios, patients with both SBP 1.4 were 7.2 times more likely to require massive transfusion than patients who did not meet both of these vital sign criteria. Conclusions Pediatric trauma patients requiring early blood transfusion present with lower blood pressures and higher heart rates, as well as higher shock indexes and lower pulse pressures. We found that shock index and systolic blood pressure are highly specific tools with promising likelihood ratios that could be used to identify patients requiring early transfusion. Levels of evidence and study type Therapeutic/Care Management, Level V.

Placenta accreta spectrum (PAS) is a group of placental invasion pathologies associated with significant morbidity to both mother and fetus. The majority of patients with PAS will require a blood transfusion at time of delivery and subsequent cesarean hysterectomy. The optimal approach to maternal acute blood loss resuscitation is currently unknown.Here, we present a cohort analysis of 34 patients with pathology-confirmed PAS treated with either whole blood (We observed comparable results in post-operative outcomes with fewer overall transfusions and subsequently, lower volumes of resuscitation (Whole blood transfusion may represent a viable option for initial resuscitation with lower resuscitation volumes and transfusion-associated complications without directly effecting post-operative outcomes in cases of PAS.

Low titer type O Rh-D + whole blood (LTO + WB) has become a first-line resuscitation medium for hemorrhagic shock in many centers around the World. Showing early effectiveness on the battlefield, LTO + WB is used in both the pre-hospital and in-hospital settings for traumatic and non-traumatic hemorrhage resuscitation. Starting in 2018, the San Antonio Whole Blood Collaborative has worked to provide LTO + WB across Southwest Texas, initially in the form of remote damage control resuscitation followed by in-hospital trauma resuscitation. This program has since expanded to include pediatric trauma resuscitation, obstetric hemorrhage, females of childbearing potential, and non-traumatic hemorrhage. The objective of this manuscript is to provide a three-year update on the successes and expansion of this system and outline resuscitation challenges in special populations.

In its 2016 report on trauma care, the National Academies of Sciences, Engineering, and Medicine called for the establishment of a National Trauma Research Action Plan to strengthen and guide future trauma research. To address this recommendation, the Department of Defense funded the Coalition for National Trauma Research to generate a comprehensive research agenda spanning the continuum of trauma and burn care. We describe the gap analysis and high priority research questions generated from the National Trauma Research Action Plan panel on injury prevention.Experts in injury prevention research were recruited to identify current gaps in injury prevention research, generate research questions and establish the priority of these questions using a consensus-driven Delphi survey approach from December 2019 through September 2020. Participants were identified using established Delphi recruitment guidelines to ensure heterogeneity and generalizability with both military and civilian representatives. Participants were encouraged, but not required, to use a Patient/Population, Intervention, Comparison, and Outcome format to generate research questions: Patient/Population; Intervention; Compare/Control; Outcome model. On subsequent surveys, participants were asked to rank the priority of each research question on a nine-point Likert scale, categorized to represent low-, medium-, and high-priority items. Consensus was defined as 60% or greater of panelists agreeing on the priority category.Twenty-eight subject matter experts generated 394 questions in 12 topic areas. By round 3 of the Delphi, 367 (93.1%) questions reached consensus, of which 169 (46.1%) were determined to be high priority, 196 (53.4%) medium priority, and 2 (0.5%) low priority. Among the 169 high priority questions, suicide (29.6%), firearm violence (20.1%), and violence prevention (18.3%) were the most prevalent topic areas.This Delphi gap analysis of injury prevention research identified 169 high priority research questions that will help guide investigators in future injury prevention research. Funding agencies and researchers should consider these gaps when they prioritize future research.Therepeutic/Care Management; Level IV.

Injury is the leading cause of death in patients aged 1 to 45 years and contributes to a significant public health burden for individuals of all ages. To achieve zero preventable deaths and disability after injury, the National Academies of Science, Engineering and Medicine called for the development of a National Trauma Research Action Plan to improve outcomes for military and civilian trauma patients. Because rapid resuscitation and prompt identification and treatment of injuries are critical in achieving optimal outcomes, a panel of experts was convened to generate high-priority research questions in the areas of acute resuscitation, initial evaluation, imaging, and definitive management on injury.Forty-three subject matter experts in trauma care and injury research were recruited to perform a gap analysis of current literature and prioritize unanswered research questions using a consensus-driven Delphi survey approach. Four Delphi rounds were conducted to generate research questions and prioritize them using a 9-point Likert scale. Research questions were stratified as low, medium, or high priority, with consensus defined as ≥60% of panelists agreeing on the priority category. Research questions were coded using a taxonomy of 118 research concepts that were standard across all National Trauma Research Action Plan panels.There were 1,422 questions generated, of which 992 (69.8%) reached consensus. Of the questions reaching consensus, 327 (33.0%) were given high priority, 621 (62.6%) medium priority, and 44 (4.4%) low priority. Pharmaceutical intervention and fluid/blood product resuscitation were most frequently scored as high-priority intervention concepts. Research questions related to traumatic brain injury, vascular injury, pelvic fracture, and venous thromboembolism prophylaxis were highly prioritized.This research gap analysis identified more than 300 high-priority research questions within the broad category of Acute Resuscitation, Initial Evaluation, Imaging, and Definitive Management. Research funding should be prioritized to address these high-priority topics in the future.

Introduction Whole blood (WB) resuscitation has been associated with a mortality benefit in trauma patients. Several small series report the safe use of WB in the pediatric trauma population. We performed a subgroup analysis of the pediatric patients from a large prospective multicenter trial comparing patients receiving WB or blood component therapy (BCT) during trauma resuscitation. We hypothesized that WB resuscitation would be safe compared to BCT resuscitation in pediatric trauma patients. Methods This study included pediatric trauma patients (0-17 y), from ten level-I trauma centers, who received any blood transfusion during initial resuscitation. Patients were included in the WB group if they received at least one unit of WB during their resuscitation, and the BCT group was composed of patients receiving traditional blood product resuscitation. The primary outcome was in-hospital mortality with secondary outcomes being complications. Multivariate logistic regression was performed to assess for mortality and complications in those treated with WB vs BCT. Results Ninety patients, with both penetrating and blunt mechanisms of injury (MOI), were enrolled in the study (WB: 62 (69%), BCT: 28 (21%)). Whole blood patients were more likely to be male. There were no differences in age, MOI, shock index, or injury severity score between groups. On logistic regression, there was no difference in complications. Mortality was not different between the groups ( P = .983). Conclusion Our data suggest WB resuscitation is safe when compared to BCT resuscitation in the care of critically injured pediatric trauma patients.

BACKGROUND The National Academies of Sciences, Engineering, and Medicine 2016 trauma system report recommended a National Trauma Research Action Plan (NTRAP) to strengthen and guide future trauma research. To address this recommendation, 11 expert panels completed a Delphi survey process to create a comprehensive research agenda, spanning the continuum of trauma care. We describe the gap analysis and high priority research questions generated from the NTRAP panel on prehospital and mass casualty trauma care. METHODS We recruited interdisciplinary national experts to identify gaps in the prehospital and mass casualty trauma evidence base and generate prioritized research questions using a consensus-driven Delphi survey approach. We included military and civilian representatives. Panelists were encouraged to use the PICO (Patient/Population, Intervention, Compare/Control, and Outcome) format to generate research questions. We conducted four Delphi rounds in which participants generated key research questions and then prioritized the questions on a 9-point Likert scale to low, medium, and high priority items. We defined consensus as ≥60% agreement on the priority category and coded research questions using a taxonomy of 118 research concepts in 9 categories. RESULTS 31 interdisciplinary subject matter experts generated 490 research questions, of which 433 (88%) reached consensus on priority. The rankings of the 433 questions were: 81 (19%) high priority, 339 (78%) medium priority, and 13 (3%) low priority. Among the 81 high priority questions, there were 46 taxonomy concepts, including: health systems of care (36 questions), interventional clinical trials and comparative effectiveness (32 questions), mortality as an outcome (30 questions); prehospital time/transport mode/level of responder (24 questions), system benchmarks (17 questions), and fluid/blood product resuscitation (17 questions).Conclusions This Delphi gap analysis of prehospital and mass casualty care identified 81 high priority research questions to guide investigators and funding agencies for future trauma research. LEVEL OF EVIDENCE not applicable.

Low titer O+ whole blood (LTOWB) is being increasingly used for resuscitation of hemorrhagic shock in military and civilian settings. The objective of this study was to identify the impact of prehospital LTOWB on survival for patients in shock receiving prehospital LTOWB transfusion.A single institutional trauma registry was queried for patients undergoing prehospital transfusion between 2015 and 2019. Patients were stratified based on prehospital LTOWB transfusion (PHT) or no prehospital transfusion (NT). Outcomes measured included emergency department (ED), 6-h and hospital mortality, change in shock index (SI), and incidence of massive transfusion. Statistical analyses were performed.A total of 538 patients met inclusion criteria. Patients undergoing PHT had worse shock physiology (median SI 1.25 vs. 0.95, p .001) with greater reversal of shock upon arrival (-0.28 vs. -0.002, p .001). In a propensity-matched group of 214 patients with prehospital shock, 58 patients underwent PHT and 156 did not. Demographics were similar between the groups. Mean improvement in SI between scene and ED was greatest for patients in the PHT group with a lower trauma bay mortality (0% vs. 7%, p = .04). No survival benefit for patients in prehospital cardiac arrest receiving LTOWB was found (p .05).This study demonstrated that trauma patients who received prehospital LTOWB transfusion had a greater improvement in SI and a reduction in early mortality. Patient with prehospital cardiac arrest did not have an improvement in survival. These findings support LTOWB use in the prehospital setting. Further multi-institutional prospective studies are needed.

Based on limited published evidence, physiological principles, clinical experience, and expertise, the author group has developed a consensus statement on the potential for iatrogenic harm with rapid sequence induction (RSI) intubation and positive-pressure ventilation (PPV) on patients in hemorrhagic shock. "In hemorrhagic shock, or any low flow (central hypovolemic) state, it should be noted that RSI and PPV are likely to cause iatrogenic harm by decreasing cardiac output." The use of RSI and PPV leads to an increased burden of shock due to a decreased cardiac output (CO)2 which is one of the primary determinants of oxygen delivery (DO2). The diminishing DO2 creates a state of systemic hypoxia, the severity of which will determine the magnitude of the shock (shock dose) and a growing deficit of oxygen, referred to as oxygen debt. Rapid accumulation of critical levels of oxygen debt results in coagulopathy and organ dysfunction and failure. Spontaneous respiration induced negative intrathoracic pressure (ITP) provides the pressure differential driving venous return. PPV subsequently increases ITP and thus right atrial pressure. The loss in pressure differential directly decreases CO and DO2 with a resultant increase in systemic hypoxia. If RSI and PPV are deemed necessary, prior or parallel resuscitation with blood products is required to mitigate post intervention reduction of DO2 and the potential for inducing cardiac arrest in the critically shocked patient.

Hemorrhagic shock remains the leading cause of preventable death on the battlefield, despite major advances in trauma care. Early initiation of balanced resuscitation has been shown to decrease mortality in the hemorrhaging patient. To address transfusion limitations in austere environments or in the event of multiple casualties, walking blood banks have been used in the combat setting with great success. Leveraging the success of the region-wide whole blood program in San Antonio, Texas, we report a novel plan that represents a model response to mass casualty incidents.

Background Death from postpartum hemorrhage (PPH) remains a significant preventable problem worldwide. Cold-stored, low-titer, type-O whole blood (LTOWB) is increasingly being used for resuscitation of injured patients, but it is uncommon in PPH patients, and it is unclear what its role may be in this population. Study design and methods Brief report of the early experience of WB use for PPH in two institutions, one university hospital and one private hospital. Results Different approaches have been implemented at the two institutions, one designed for emergency release, uncrossmatched transfusion of LTOWB as part of a massive transfusion protocol (MTP) and one for high-risk obstetric patients with known placental abnormalities. A total of 7 PPH patients have received a total of 17 units of LTOWB between the two institutions. No severe adverse transfusion reactions were observed clinically in either institution and the clinical outcomes were favorable in all cases. Conclusion In our early experience, LTOWB can be implemented for two different PPH clinical scenarios. Larger studies are needed to compare outcomes between LTOWB and traditional component resuscitation strategies.

Whole blood (WB) transfusion for trauma patients with severe hemorrhage has demonstrated early successful outcomes compared to conventional component therapy. The objective of this study was to demonstrate WB transfusion in the non-trauma patient. Consecutive adult patients receiving WB transfusion at a single academic institution were reviewed from February 2018 to January 2020. Outcomes measured were mortality and transfusion-related reactions. A total of 237 patients who received WB were identified with 55 (23.2%) non-trauma patients. Eight patients (14.5%) received pre-hospital WB. The most common etiology of non-traumatic hemorrhage was gastrointestinal bleeding (43.6%, n = 24/55). Approximately half of the non-trauma patients (n = 28/55) received component therapy. Transfusion-related events occurred in 3 patients. This study demonstrated that non-trauma patients could receive WB transfusions safely with infrequent transfusion-related events. Future studies should focus on determining if outcomes are improved in non-trauma patients who receive WB transfusions and defining specific transfusion criteria for this population.

Four divalent metal coordination polymers containing bis(4-pyridylmethyl)piperazine (4-bpmp) and the ortho -dicarboxylate ligands phthalate (pht) or 4-methylphthalate (mpht) have been prepared by solvent diffusion or hydrothermal methods. {[Cu 2 (pht) 2 (H4-bpmp) 2 (H 2 O) 2 ](NO 3 ) 2 ·H 2 O} n ( 1 ) and {[Cu 2 (pht) 2 (H4-bpmp) 2 (H 2 O) 2 ](SO 4 )·2H 2 O} n ( 2 ) possess chiral cationic layer motifs formed by the junction of [Cu(H 2 O)(pht)] n chains by tethering curled-conformation H4-bpmp + ligands. {[Co(pht)(H 2 O)(4-bpmp)]·5.5H 2 O} n ( 3 ) displays a (4,4) grid constructed from anti-syn carboxylate-bridged {Co 2 (H 2 O) 2 (pht) 2 } dimeric clusters linked by open-conformation 4-bpmp ligands. {[Cd 2 (mpht) 2 (H 2 O) 2 (4-bpmp)(H4-bpmp)]ClO 4 ·4H 2 O} n ( 4 ) manifests cationic layered motifs based on neutral [Cd 2 (H 2 O) 2 (mpht) 2 ] dinuclear units with {CdOC 4 O} 2 12-membered circuits, linked by open-conformation 4-bpmp and H4-bpmp + ligands. Variable-temperature magnetic data indicate likely concomitant zero-field splitting and ferromagnetic coupling in 3 . Violet light emission is observed when 4 is subjected to ultraviolet irradiation.

Hydrothermal synthesis has afforded a pair of divalent cobalt coordination polymers containing meta-substituted benzenedicarboxylate and 4,4′-dipyridylamine (dpa) ligands, in which the length of the pendant arms on the anionic components dictates the overall dimensionality. [Co(1,3-phda)(dpa)(H2O)]n (1, 1,3-phda = 1,3-phenylenediacetate) possesses a ruffled (4,4) rhomboid grid 2-D layered structure with an 5-connected sqp supramolecular net. Use of a meta-substituted benzenedicarboxylate with shorter pendant arms generated {[Co(1,3-bdc)(dpa)]·3H2O}n (2, 1,3-bdc = 1,3-benzenedicarboxylate), which displays a 3-D network structure with 658 topology. Antiferromagnetic coupling, in conjunction with zero-field splitting, was evident across the supramolecular Co–O–H⋯O–Co patterns in 1 and the syn–syn bridged {Co(OCO)}2 dimeric units in 2.

Hydrothermal synthesis has afforded four divalent metal 1,3-phenylenediacetate (1,3-phda) coordination polymers containing different dipyridyl-type ligands. {[Cu(1,3-phda)(dpa)(H2O)]·H2O}n (1, dpa = 4,4′-dipyridylamine) exhibits a simple 2-D (4,4) rhomboid grid structure. {[Co(1,3-phda)(bpy)]·1.5H2O}n (2, bpy = 4,4′-bipyridine) also possesses a (4,4) layer structure, but with syn–syn bridged {Co2(OCO)2} dimeric kernels serving as 4-connected nodes. {[Co(H2O)4(3-bpmpH2)](1,3-phda)2·8H2O}n (3, 3-bpmp = bis(3-pyridylmethyl)piperazine) manifests cationic 1-D [Co(H2O)4(3-bpmpH2)]n4n+ chains linked into higher dimensionality by unligated 1,3-phda anions and curled tetrameric water molecule units. {[Ni(1,3-phda)(4-bpmp)(H2O)2]·2H2O}n (4, 4-bpmp = bis(4-pyridylmethyl)piperazine) has an underlying twofold interpenetrated 658 (cds) 3-D network topology. Variable temperature magnetic susceptibility studies revealed the presence of weak antiferromagnetic coupling and zero-field splitting (J = −1.65(4) cm−1 and D = 30.9(7) cm−1 with g = 2.20(1)) within the {Co2(OCO)2} dimers in 2.

Three divalent copper coordination polymers containing aromatic dicarboxylate ligands and the long-spanning tethering imine bis(4-pyridylmethyl)piperazine (bpmp) have been prepared and structurally characterized. The length of the dicarboxylate pendant arms, carboxylate binding mode, and the inclusion of anionic components play a synergistic role in structure direction in this system. {[Cu(ip)(bpmp)(H 2 O)]·5H 2 O} n (ip = isophthalate, 1 ) displays neutral (4,4) rectangular coordination polymer grids that stack in an ABCD repeat pattern. Use of the longer pendant arm dicarboxylate 1,3-phenylenediacetate (phda) resulted in {[Cu 2 (phda) 2 (bpmp)]·H 2 O} n ( 2 ), a 3-D network coordination polymer with primitive cubic topology that features strongly antiferromagnetically coupled ( J = −331(1) cm −1 ) {Cu 2 (CO 2 ) 4 } paddlewheel units. In the presence of excess nitrate ions, {[Cu(phda)(Hbpmp)](NO 3 )·3H 2 O} n ( 3 ) was isolated instead of 2 ; 3 manifests cationic 2-D coordination polymer layers built from weakly antiferromagnetically coupled ( J = −2.43(1) cm −1 ) {Cu 2 O 2 } dimers linked through phda and protonated bpmp ligands. The striking difference in magnetic properties is ascribed to the equatorial–equatorial versus axial–equatorial bridging of copper coordination spheres in 2 and 3 , respectively.

Four divalent copper coordination polymers containing both 1,2-phenylenediacetate (1,2-phda) and dipyridyl-type coligands have been prepared and structurally characterized by single-crystal X-ray diffraction. {[Cu(1,2-phda)(dpa)]·H2O}n (1, dpa = 4,4′-dipyridylamine) possesses a simple (4,4) rhomboid polymeric grid structure but can be considered a (4,6)-connected binodal supramolecular lattice with (4462)(446108) fsc topology. Use of a longer dipyridyl ligand afforded [Cu2(1,2-phda)2(dpp)]n (2, dpp = 1,3-di(4-pyridyl)propane), which manifests a rare self-penetrated rob lattice (48668 topology) built from the linkage of copper dicarboxylate layers through crossed dpp tethers. [Cu(1,2-phda)(H2O)(4-bpmp)0.5]n (3, 4-bpmp = bis(4-pyridylmethyl)piperazine) forms a 5-connected Archimedean cem layer with 334453 topology. The topology of 3 can be alternately described as a 3,4-connected binodal layer with a V2O5-type network. Incorporation of nitrate counterions led to formation of {[Cu(1,2-phda)(H2O)(H4-bpmp)] (N...

Hydrothermal synthesis has afforded a pair of divalent copper coordination polymers containing the kinked and hydrogen-bonding capable imine 4,4′-dipyridylamine (dpa) and aromatic dicarboxylates, {[Cu(iph)(dpa)]·0.5H2O}n (1, iph = isophthalate) and [Cu(tdc)(dpa)]n (2, tdc = 2,5-thiophenedicarboxylate). Compounds 1 and 2 contain orthogonally disposed parallel sets of 1-D [Cu(iph)]n and [Cu(tdc)]n chains, respectively, containing dicarboxylate-bridged dinuclear {CuOCO}2 units. The chain motifs are joined by tethering dpa ligands to construct uncommon non-interpenetrated 3-D CdSO4 lattices (658 topology) in both cases. Variable temperature magnetic studies show the presence of weak antiferromagnetic coupling within the {CuOCO}2 dimers in both complexes, with J = −2.66(3) and −1.68(5) cm−1 for 1 and 2, respectively.

Hydrothermal synthesis has afforded three cadmium coordination polymers incorporating both an aromatic dicarboxylate ligand and the kinked and hydrogen-bonding capable organodiimine 4,4′-dipyridylamine (dpa). The positions and length of the pendant arms of the aromatric dicarboxylate moiety exerts a strong structure directing effect in this system. {[Cd(hmph)(dpa)] · H2O}n (1, hmph = homophthalate) possesses interdigitated herringbone (6,3) grid layers with an ABAB stacking pattern. {[Cd(1,3-phda)(dpa)(H2O)] · 0.5H2O}n (2, 1,3-phda = 1,3-phenylenediacetate) exhibits a (4,4)-grid layer structure with two different aperture sizes and an unusual ABCD layer stacking pattern. Shortening the pendant arm length resulted in an uncommon CdSO4-type (658 topology) 4-connected 3-D network in {[Cd(iph)(dpa)] · 4H2O}n (3, iph = isophthalate), whose uncoordinated water molecules occupy a sizable incipient void space of 23.7% of the unit cell volume. All three coordination polymers underwent blue-violet luminescence under ultraviolet irradiation.

The acentric coordination polymer {[Cd(dms)(4,4′-bpy)(H2O)2] · H2O}n (1, dms = 2,2-dimethylsuccinate, 4,4′-bpy = 4,4′-bipyridine) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. Fourfold one-dimensional (1-D) homochiral right-handed helical [Cd(dms)]n chain motifs are conjoined through tethering 4,4′-bpy ligands to construct a three-dimensional (3-D) network with uncommon CdSO4 (658) topology. Irradition of 1 with ultraviolet light results in blue–violet luminescence.

Hydrothermal synthesis has afforded three nickel coordination polymers incorporating both aromatic dicarboxylates and the kinked and hydrogen bonding capable organodiimine 4,4′-dipyridylamine (dpa). These were characterized by single-crystal X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. [Ni(1,2-phda)(dpa)(H2O)]n (1,2-phda = 1,2-phenylenediacetate, 1) displays (4,4) rhomboid grid-like 2D layers that aggregate into 3D through O–H⋯O hydrogen bonding. Shortening one of the pendant arms of the dicarboxylate ligand resulted in a shift to (6,3) herringbone style 2D coordination layer motifs in {[Ni(hmph)(dpa)] · 1.33H2O}n (hmph = homophthalate, 2), which stack in an AA′B pattern. [Ni(1,3-phda)(dpa)(μ-H2O)0.5]n (1,3-phda = 1,3-phenylenediacetate, 3) manifests a canted primitive cubic type coordination polymer lattice constructed from dinuclear {Ni2(μ-H2O)} kernels linked into 3D through tethering 1,3-phda and dpa ligands. Analysis of the variable temperature magnetic susceptibility of 3 indicated the presence of antiferromagnetic superexchange within its dinuclear units (g = 2.290(2), J = −4.21(2) cm−1).

The novel coordination polymer {[Co(Hbtc)(4-bpmp)(H2O)] · 3H2O} (1, btc = 1,3,5-benzenetricarboxylate, 4-bpmp = N,N′-bis(4-pyridylmethyl)piperazine) has been prepared by hydrothermal synthesis and characterized by single crystal X-ray diffraction, IR and thermogravimetric analysis. Individual [Co(Hbtc)(4-bpmp)(H2O)]n layers mutually interpenetrate in a 2d + 2d → 3D inclined fashion to produce channels coursing down the c crystal direction, occupied by “infinite” 1D water molecule chains. Dehydration of 1 results in structural reorganization to a monoclinic phase, which is converted to an amorphous phase upon rehydration.

Hydrothermal synthesis has afforded two divalent metal coordination complexes incorporating both fully deprotonated pyromellitate (pyro) anions and the kinked dipodal organodiimine 4,4′-dipyridylamine (dpa), {[Co(H2O)4(Hdpa)2][pyro]} (1) and {[H2dpa][Zn(pyro)]·2H2O} (2). Both new complexes were characterized by single crystal X-ray diffraction and spectral and thermogravimetric analyses. Complex 1 possesses discrete [Co(H2O)4(Hdpa)2]4+ cations linked into supramolecular 2-D (4,4) rhomboid grid layer motifs by hydrogen bonding between the unligated pyro anions and the aquo ligands. The pendant, monodentate Hdpa+ cations also engage in charge-separated hydrogen bonding to pyro anions in neighboring layers, resulting in a supramolecular 3-D structure with an unprecedented 6-connected 446108 topology. In contrast, 2 is a true coordination polymer, with divalent Zn atoms linked by ligated pyro anions into a binodal 4-connected PtS-type anionic network (4284 topology), which encapsulates H2dpa2+ cations and unligated water molecules within large incipient pores coursing through the structure. Irradiation of a solid sample of 2 with ultraviolet light resulted in blue-light emission, likely indicative of π–π* transitions within the orbital manifolds of both the pyro anions and unligated H2dpa2+ cations.

Hydrothermal synthesis has afforded a family of divalent metal coordination polymers incorporating both the isophthalate dianion (ip) and the flexible organodiimine N,N′-bis(4-pyridylmethyl)piperazine (bpmp). The compounds of type {[M(ip)(bpmp)]·H2O} (M = Co, 1; M = Cd, 2) are isomorphous, possessing puckered two dimensional (2D) rectangular grid layers built from the linkage of [M2(ip)2] double chains through bpmp tethers. In contrast, the nickel congener {[Ni(ip)(bpmp)(H2O)]·H2O} (3) displays a corrugated, interpenetrated 2D structure. {[Zn(ip)(bpmp)]·H2O} (4) adopts a 5-fold interpenetrated three-dimensional diamondoid topology due to the tetrahedral coordination at Zn. Analysis of the variable temperature magnetic susceptibility of 1 indicated the presence of ferromagnetic coupling and zero-field splitting effects within the dinuclear subunits along with possible long-range ferromagnetic interactions transmitted through the ip ligands. The d10 derivatives 2 and 4 exhibited blue-violet luminescence upo...

Hydrothermal synthesis has afforded a series of zinc-containing coordination polymers incorporating the kinked organodiimine 4,4′-dipyridylamine (dpa) and phenylenediacetate (phda) isomers. {[Zn(1,4-phda)(dpa)]·H2O}∞ (1) manifests a two-dimensional (2D) corrugated layer morphology. While both {[Zn(1,2-phda)(dpa)]·2H2O}∞ (2) and [Zn(1,3-phda)(dpa)]∞ (3) contain three-dimensional 4-fold interpenetrated coordination polymer networks, 2 possesses the SrAl2 structure type (sra, 42638 topology) but the acentric material 3 adopts the diamond structure type (dia, 66 topology). The varying morphologies thus reveal a significant structure-directing effect of the position of the acetate groups during self-assembly of these coordination polymers. Hydrogen-bonding mechanisms imparted by the central amine group of the dpa ligand provide ancillary supramolecular structure-directing effects in all three cases. All three materials undergo blue–violet luminescence upon irradiation with ultraviolet light.

Hydrothermal treatment of zinc chloride, 1,3,5-benzenetricarboxylic acid (H3BTC), and 4,4′-dipyridylamine (dpa) afforded two different complexes depending on reaction conditions, which were characterized by single-crystal X-ray diffraction, infrared spectroscopy, and elemental analysis. Under acidic conditions, a discrete neutral molecular species with formulation [Zn(HBTC)2(Hdpa)2] (1) was isolated, which aggregates into two-dimensional hydrogen-bonded layers. Under more basic conditions, the two-dimensional layered coordination polymer [Zn(BTC)(Hdpa)] (2) is obtained, which manifests covalent linkage of [Zn(BTC)(Hdpa)] serpentine chain motifs into 3-connected undulating 4.82 topology 2-D layers. Both 1 and 2 possess tetrahedral coordination at Zn. Use of cadmium nitrate in the synthesis resulted in [Cd(BTC)(H2O)(Hdpa)] (3), which displays a similar layer topology as 2 but with significant adjustments imparted by octahedral coordination at Cd. In all cases, supramolecular hydrogen bonding promoted by Hdpa ligands provide an important assistive structure-directing role. All materials display blue luminescence upon excitation with ultraviolet light, ascribed to intraligand transitions. Crystallographic data: 1: monoclinic, C2/c, a=25.389(6) A, b=9.811(2) A, c=17.309(4) A, and β=128.957(3)°, 2: monoclinic, P21/c, a=13.212(17)c, b=17.15(2) A, c=7.506(10) A, and β=93.71(2)°, and 3: monoclinic, C2/c, a=14.241(6) A, b=15.218(6) A, c=17.976(7) A, and β=109.330(6)°.

Hydrothermal synthesis has afforded a family of three structurally related metal phthalate (pht) 1-D coordination polymers incorporating the kinked dipodal organodiimine 4,4′-dipyridylamine (dpa), with a general formulation of [L2M(dpa)2M(H2O)4] · H2O (L = pht, M = Co, 1, M = Ni, 2; L = 4-methylphthalate (4-mpht), M = Co, 3). Single crystal X-ray diffraction of 1 and 2 revealed the presence of one-dimensional (1-D) polymeric chains consisting of [M(H2O)4]2+ and [M(pht)2]2− subunits linked through dpa tethers. These chains in turn conjoin into pseudo 2-D layers and 3-D networks via extensive supramolecular hydrogen bonding pathways. An extremely similar structure is observed for 3 despite the presence of the bulkier methyl group substituent. 1–3 were further characterized via infrared spectroscopy and elemental and thermogravimetric analysis. 1–3 represent the first dicarboxylate coordination polymers incorporating dpa tethering ligands.

The divalent nickel isothiocyanate coordination polymer [Ni(NCS)2(dpa)2] (1) has been prepared in high yield via the hydrothermal combination of Ni(SCN)2 with the kinked tethering ligand 4,4′-dipyridylamine (dpa), and characterized via single crystal X-ray diffraction, infrared spectroscopy and elemental and thermal analysis. 1 manifests offset stacked 2-D (4,4)-topology layered motifs organized into 3-D via interlamellar supramolecular N–H···S hydrogen bonding. Hydrothermal reaction of CuCl2·2H2O, NaSCN, and dpa afforded the copper (I) thiocyanate coordination polymer [Cu2(SCN)2(dpa)] (2), whose single crystal structure revealed unprecedented 1-D [Cu2(SCN)2] zig-zag staircase motifs constructed via connection of the Cu2S2 “stair steps” at their adjacent sides via μ3-1,1,3-SCN anions. The 3-D structure of 2 is propagated by covalent linkage of each [Cu2(SCN)2] staircase to four others through dipodal dpa tethering ligands, enhanced by N–H···S and C–H···S supramolecular interactions to two other staircases.

Copper phthalate coordination polymers incorporating the kinked and hydrogen-bonding-capable imines 4,4'-dipyridylketone (dpk) and 4,4'-dipyridylamine (dpa) have been prepared and structurally characterized by single-crystal X-ray diffraction. {[Cu(pht)(dpk)].0.33CH(3)OH}(n) (1; pht = phthalate) possesses helical subunits built from the fusion of [Cu(dpk)](n) 3-fold double helices and [Cu(pht)](n) 3-fold helices with opposite handedness. The resulting achiral [Cu(pht)(dpk)](n) helices are conjoined by bridging phthalate carboxylate oxygen atoms to construct {Cu(2)O(2)} dimeric units, which serve as 8-connected nodes for a three-dimensional (3D) coordination polymer lattice with an unprecedented 3(6)4(12)5(8)6(2) topology, evocative of a 3D Kagome lattice. {[Cu(2)(pht)(2)(dpa)].H(2)O}(n) (2) manifests homochiral septuple left-handed [Cu(2)O(2)(dpa)](n) helices formed by copper ions, phthalate oxygen atoms, and dpa ligands. The septuple helices are bracketed by pht anions to construct chiral one-dimensional nanobarrels with solvent-free "star-shaped" channels. Compounds 1 and 2 display antiferromagnetic [J = -9.85(5) cm(-1)] and ferromagnetic [J = +1.36(3) cm(-1)] coupling across their {Cu(2)O(2)} dimeric units, respectively.

In the title compound, {(C(10)H(11)N(3))[Zn(3)(C(8)H(4)O(4))(4)]·2H(2)O}(n), divalent Zn atoms are linked into trinuclear units featuring tetra-hedral, octa-hedral and distorted tetrahedral, octahedral and square-pyramidal coordination geometries. These trinuclear units are connected by isopthalate dianions into [Zn(3)(isophthalate)(4)](n) (2n-) anionic layers, which aggregate into the three-dimensional structure via hydrogen-bonding pathways mediated by doubly protonated 4,4'-imino-dipyridinium cations and water mol-ecules of crystallization. One solvent water mol-ecule was found to be disordered over two positions, each with a 50% site-occupancy factor.

In the title compound, {(C10H11N3)[Zn3(C8H4O4)4]·2H2O}n, divalent Zn atoms are linked into trinuclear units featuring tetra­hedral, octa­hedral and distorted tetrahedral, octahedral and square-pyramidal coordination geometries. These trinuclear units are connected by isopthalate dianions into [Zn3(isophthalate)4]n2n− anionic layers, which aggregate into the three-dimensional structure via hydrogen-bonding pathways mediated by doubly protonated 4,4′-imino­dipyridinium cations and water mol­ecules of crystallization. One solvent water mol­ecule was found to be disordered over two positions, each with a 50% site-occupancy factor.

In the title compound, [Ni(C8H4O4)(C10H9N3)3] n , an NiII atom with octahedral coordination is bound by one chelating terephthalate (tp) dianion, two monodentate di-4-pyridylamine (dpa) ligands, and two bridging dpa ligands. These link the Ni atoms into one-dimensional [Ni(tp)(dpa)3] n coordination polymer chains that propagate along the b-axis direction. Interweaving pairs of chains stack in three dimensions via N—H...O hydrogen bonding.

In the title hydrated salt, C10H11N2+·C8H4O5−·3H2O, doubly protonated 4,4′-dipyridylamine mol­ecules engage in N—H⋯O hydrogen bonding with 5-hydroxy­isophthalate dianions to form undulating one-dimensional chains, which aggregate into three dimensions by O—H⋯O and N—H⋯O hydrogen-bonding patterns mediated by water mol­ecules of crystallization.